Email Deliverability Guide 2026

What is Email Deliverability?

 

Email deliverability is a crucial aspect of email marketing that determines whether an email successfully reaches the recipient's inbox. Optimizing email campaigns involves addressing common issues that affect inbox placement.

Features such as AI spam trigger detection, spam scoring, and HTML Sanitizing help identify and rectify potential problems in email content before sending emails. Additionally, tools to manage preheaders, resize and optimize images, remove problematic elements like non-ASCII characters, and remove redundant CSS help ensure emails are not flagged by spam filters and are displayed correctly across all email clients.

Enhancing deliverability also involves focusing on content and link management. Tools like blacklist link checkers, broken link checkers, and text-to-link analysis ensure that links within emails do not trigger spam filters. Features for managing ALT tags, title tags, and font sizes improve accessibility and readability, which can positively impact recipient engagement. By using comprehensive tools to create well-optimized, engaging emails, businesses can increase the likelihood of their messages reaching the audience's inboxes, maximizing the effectiveness of their email marketing campaigns.

To further improve email deliverability, it's essential to set up SPF, DMARC, and DKIM to authenticate your emails and protect against spoofing. Implementing a one-click unsubscribe option ensures compliance with regulations and maintains a clean email list. Segmenting your audience allows for more targeted and relevant content, increasing engagement. Warmup strategies help build a positive sender reputation by gradually increasing email volume. Monitoring your sender reputation and making adjustments based on feedback ensures ongoing deliverability success.

In this guide, we'll cover all these topics and more to help you achieve optimal email deliverability.

Email Authentication

 

What is SPF?

 

SPF (Sender Policy Framework) is a system that helps protect email users from spam and phishing. It works by allowing the owner of an email domain (like example.com) to specify which mail servers are allowed to send emails on behalf of their domain. This information is stored in a special SPF record in DNS. When an email is sent, the receiving server checks this record to make sure the email is coming from an approved server. The check is done on the return-path address, also known as the bounce address or mailfrom.5321 address, which is the address used for handling bounces and errors. If the email isn't from an approved server, it may be marked as spam or rejected.

 

Using SPF helps ensure that emails are legitimate and reduces the risk of fake emails from your domain.

Here is an example of a SPF DNS TXT record:

This is the FROM header that is used for the SPF Check:

Return-Path: <bounces@example.com> <-- SPF Domain Check
From: John Doe <john.doe@example.com>
To: Jane Smith <jane.smith@example.com>
Subject: Your Invoice for June 2024


 

SPF Tools:

• Look up your SPF Record Here: SPF Lookup Tool
• Create your SPF Record Here: SPF Generator

 

For more information, you can refer to the official SPF specification: RFC 7208

What is DKIM?

 

DKIM (DomainKeys Identified Mail) is an email security feature that helps ensure the authenticity of an email. It works by adding a digital signature to the email's header, which can be verified by the receiving server. The signature is created using a private key that only the domain owner has, and it corresponds to a public key published in the domain's DNS records. This process verifies that the email really comes from the claimed domain and hasn't been altered during transit. The check is done on the "From" address, also known as the mailfrom.5322 address, which indicates the sender of the email. By using DKIM, you can help protect your emails from being spoofed and ensure they are trusted by recipients.

 

Here is an example of a DKIM DNS TXT record:

This is the the FROM header that is used for the DKIM Check:

Return-Path: <bounces@example.com>
From: <bounces@example.com> <-- DKIM Domain Check
To: Jane Smith <jane.smith@example.com>
Subject: Your Invoice for June 2024


 

DKIM Tools:

• Look up your DKIM Record Here: DKIM Lookup Tool
• Create your DKIM Record Here: DKIM Generator

 

For more information, you can refer to the official DKIM specification: RFC 6376

 

What is DMARC?

 

DMARC (Domain-based Message Authentication, Reporting, and Conformance) is an email security protocol that builds on SPF and DKIM to provide stronger protection against email spoofing and phishing. DMARC allows domain owners to specify how their emails should be handled if they fail SPF or DKIM checks. When an email is sent, DMARC verifies that either the SPF or DKIM check passes and that the domain in the "From" header aligns with the domain used in the SPF or DKIM check. If both checks fail, DMARC can instruct the receiving server to reject, quarantine, or allow the email based on the domain owner's policy. This helps ensure that only legitimate emails are delivered and provides feedback to domain owners about suspicious activity, improving overall email security.

Here is an example of a DMARC DNS TXT record:

• Look up your DMARC Record Here: DMARC Lookup Tool
• Create your DMARC Record Here: DMARC Generator

 

DMARC Monitoring Services:

 

DMARC monitoring services help organizations protect their domains from email spoofing, phishing attacks, and unauthorized use. These services ensure that only legitimate email from your domain reaches your recipients by providing detailed reports on email authentication results. With DMARC monitoring, businesses gain insights into who is sending emails on their behalf and whether those messages pass or fail authentication checks (like SPF and DKIM). By analyzing these reports, organizations can identify potential vulnerabilities, track down abuse, and refine their email policies to ensure better inbox delivery and security. Additionally, these services often include real-time alerts, comprehensive dashboards, and expert recommendations to help organizations improve email authentication practices and maintain a robust defense against email fraud.

• DMARC Monitoring Service: DMARC Report

 

Identifier Alignments

 

Identifier Alignment in email refers to the process of ensuring that the identifiers used in various parts of an email system - like domain names - are aligned or match, particularly for purposes of email authentication. The primary goal of identifier alignment is to prevent email spoofing and phishing by ensuring the legitimacy of the email sender.

SPF (Sender Policy Framework):

 

• SPF Alignment occurs when the domain in the "Envelope From" address (used in the SMTP conversation) matches the domain in the "Header From" address (visible to the recipient).
• How it works: SPF checks whether the IP address sending the email is authorized to send on behalf of the "Envelope From" domain. If these domains match, SPF is aligned.

 

DKIM (DomainKeys Identified Mail)

 

• DKIM Alignment occurs when the domain in the DKIM "d=signature" (the domain used in signing the message) matches the domain in the "Header From" address.
• How it works: DKIM signs the email with a cryptographic signature. If the domain in the signature matches the domain in the "Header From" field, DKIM is aligned.

 

DMARC (Domain-based Message Authentication, Reporting & Conformance)

 

• DMARC Alignment ensures that both SPF and DKIM are aligned with the domain in the "Header From" address.
• How it works: DMARC policy checks both SPF and DKIM alignment. For a message to pass DMARC, either SPF or DKIM (or both) must be aligned.

 

Types of Alignment

 

• Strict Alignment: The domain must exactly match between the identifiers (e.g., example.com matches example.com).
• Relaxed Alignment: A subdomain can match the parent domain (e.g., mail.example.com matches example.com).

 

Example

 

If an email is sent from noreply@company.com and the SPF "Envelope From" address is also company.com, then the identifiers are aligned. However, if the "Header From" address is marketing.company.com, this would not align under strict alignment but would align under relaxed alignment.

Importance of Identifier Alignment

 

• Prevents spoofing: Ensuring that identifiers align helps prove that the email is coming from the actual domain and not a malicious source.
• Builds trust: Recipients and email servers are more likely to trust an email with proper alignment, improving deliverability.
• Passes DMARC policy: Without proper alignment, DMARC can fail, which may lead to emails being rejected or marked as spam.

 

What is FCrDNS?

 

FCrDNS (Forward Confirmed reverse DNS) is a method used to verify the authenticity of an email sender's IP address. It ensures that the domain associated with an IP address has a valid reverse DNS (rDNS) record, and that this reverse lookup matches a valid forward DNS (the hostname).

How it works

 

• Forward DNS:The DNS system resolves a domain name to an IP address (e.g., mail.example.com → 192.168.1.1).
• Reverse DNS (rDNS): The reverse process resolves the IP address back to a domain name (e.g., 192.168.1.1 → mail.example.com).
• FCrDNS Check: FCrDNS confirms that the forward and reverse lookups match. In other words, the IP resolves to a domain name, and that domain name resolves back to the same IP.

 

Why FCrDNS is important

 

• Legitimacy: It helps validate the identity of the email sender. If FCrDNS passes, it indicates that the IP address is correctly configured, and the sender is more likely to be legitimate.
• Spam Filtering: Many spam filters use FCrDNS as one factor in determining whether to trust an email source. Failing FCrDNS can increase the likelihood of emails being marked as spam.
• Email Deliverability: Many spam filters use FCrDNS as one factor in determining whether to trust an email source. Failing FCrDNS can increase the likelihood of emails being marked as spam.Having FCrDNS correctly configured can improve email deliverability, as servers are more likely to trust mail coming from verified IP addresses.

 

FCrDNS and Authentication

 

While it's not an authentication protocol like SPF, DKIM, or DMARC, FCrDNS adds an extra layer of trust for the sender's identity. It verifies the proper DNS setup for email servers, helping with both security and deliverability.

When to use it

 

Most reputable email servers are configured with FCrDNS, and it's a best practice to ensure that your mail server has both forward and reverse DNS records that match, particularly if you're managing email campaigns or running an email server.

 

Where to TEST?

 

To test your email authentication use our eMail Tester.

 

DNS Records

 

What is a PTR Record?

 

A PTR record, also known as a reverse DNS (rDNS) record, maps an IP address to a domain name, which is the opposite of an A record that maps a domain name to an IP address. In email delivery, PTR records are used to help verify the legitimacy of the sending server. When an email is received, the receiving server can look up the PTR record of the sending server's IP address to check if it corresponds to a valid domain name. While a direct match between the domain in the email and the PTR record isn't always necessary - especially when using an Email Service Provider (ESP) - having a properly configured PTR record still helps improve email deliverability. It shows that the sending IP address is authorized and trusted, reducing the likelihood of the email being marked as spam.

 

What is a Generic PTR Record and why is shouldn't be used?

 

A generic PTR (pointer) record is a type of DNS record used for reverse DNS lookups, mapping an IP address back to a domain name. These records are often assigned by ISPs or hosting providers and follow a specific pattern, which can sometimes look suspicious to spam filters.

Examples of a Generic PTR Records:

 

• 1-2-3-4-dynamic-ip.example.com: Indicates a dynamic IP address assigned by an ISP.
• 11-22-33-44-host.hostingcompany.com: Shows a hosting provider's address, likely shared by multiple users.
• 5-6-7-8.residential.customerisp.com: Suggests a residential IP address provided by an ISP.
• 4.3.2.1.in-addr.arpa: This is a standard format for reverse DNS entries, showing an IP address in reverse order, often used in PTR records for mapping IP addresses to domain names.

 

While these generic PTR records are functional, they are not ideal for sending email because many mail servers and spam filters, like AT&T, view them with suspicion. This is because dynamically assigned or generic IP addresses are frequently associated with spam or poorly configured mail servers. To improve email deliverability, it is recommended to use a properly configured, dedicated IP address with a custom PTR record that accurately reflects your domain, such as "mail.yourdomain.com". This helps establish trust and improves the chances that your emails will be successfully delivered and not marked as spam.

 

Here is an example of a PTR DNS record:

PTR Lookup Tools:

 

• PTR Lookup

 

What are MX Records?

 

MX (Mail Exchange) records are essential DNS records that specify the mail servers responsible for receiving email on behalf of a domain. Having properly configured MX records ensures that your domain can receive emails reliably. It is crucial to set up MX records for both the mailfrom.5321 address (used in the SMTP envelope) and the 5322 address (the "From" address shown to email recipients). The MX record for the mailfrom.5321 address is necessary to receive bounce messages, which help you manage undeliverable emails. The MX record for the 5322 address is important for handling unsubscribe requests and stop replies. Additionally, spam filters perform a check called backscatter to verify the validity of MX records. Properly configured MX records improve email deliverability and trustworthiness by ensuring that your domain can handle email traffic correctly and pass spam filter checks.

 

Here is an example of a MX DNS record:

 

Backup MX Records

 

Backup MX (Mail Exchange) records serve as a critical failover mechanism for email delivery, ensuring that incoming email is not lost if the primary mail server becomes unavailable. MX records in DNS specify the mail servers responsible for receiving emails on behalf of a domain, with each record assigned a priority value. The primary mail server has the highest priority (lowest numerical value), while secondary servers have higher priority values (higher numerical values).

When an email is sent, the sender's mail server looks up the recipient domain's MX records and attempts delivery to the server with the highest priority. If the primary server is down, the sender's server will try the next available server in the priority order. This setup ensures that emails are not lost during outages, providing increased reliability and redundancy for email communication.

MX Lookup Tools:

 

• MX Lookup
• whatsmydns.net

 

Mail Server Configuration

 

What is an SMTP Greeting?

 

The SMTP (Simple Mail Transfer Protocol) greeting is the initial message sent by an email server when it connects to another server to initiate the process of sending an email. This greeting typically includes the server's hostname and may also include additional information about the server's capabilities. The role of the SMTP greeting is crucial in establishing a connection and ensuring smooth communication between email servers.

 

Key Roles of the SMTP Greeting

 

• Identification: It identifies the sending server to the receiving server, allowing for proper verification and authentication.
• Trust Building: A well-configured SMTP greeting that includes the correct server hostname and additional relevant information can help build trust with the receiving server, improving email deliverability.
• Spam Filtering: Many spam filters check the SMTP greeting to ensure it matches the expected format and information. Inconsistencies or generic greetings may raise red flags, potentially marking the email as spam.
• Error Handling: If there are any issues with the SMTP connection, the initial greeting can help diagnose problems by providing clear identification and a starting point for troubleshooting.

 

Understanding Email Ports and Their Responsibilities

 

For proper email communication, certain ports need to be open. Each port has a specific role in the process of sending and receiving emails. Here are the key ports and their responsibilities:

Common Email Ports

 

• Port 25 (SMTP):

  Used for sending emails between mail servers. This is the standard port for SMTP (Simple Mail Transfer Protocol) and is used for server-to-server email transmission.

• Port 587 (SMTP Submission):

  Used for submitting email from an email client to a mail server. This port should be used by email clients (like Outlook or Thunderbird) to send outgoing mail, and it requires authentication.

• Port 465 (SMTPS):

  Used for SMTP over SSL (Secure Sockets Layer). This port is used for secure email transmission and also requires authentication.

• Port 110 (POP3):

  Used for retrieving emails from a mail server. This is the standard port for POP3 (Post Office Protocol version 3), which allows email clients to download emails from the server.

• Port 995 (POP3S):

  Used for POP3 over SSL. This port provides secure email retrieval using POP3.

• Port 143 (IMAP):

  Used for accessing emails on a mail server. This is the standard port for IMAP (Internet Message Access Protocol), which allows email clients to access and manage emails directly on the server.

• Port 993 (IMAPS):

  Used for IMAP over SSL. This port provides secure email access and management using IMAP.

 

Ensuring the ports you are using are open and properly configured is essential for smooth email communication. Each port serves a specific function, whether it’s for sending, receiving, or accessing emails securely. Proper configuration and use of these ports help maintain secure and efficient email operations.

 

Open Relays and How to Prevent Them

 

An open relay is a mail server that allows anyone on the internet to send email through it, not just email from or to known users. This can be exploited by spammers to send large volumes of junk email, which can lead to the server being blacklisted and other issues.

Preventing Open Relays

 

To prevent your mail server from becoming an open relay:

• Require Authentication: Configure your server to require authentication for all outgoing emails. This ensures that only authorized users can send emails through your server.
• Restrict IP Addresses: Limit the range of IP addresses that can connect to your server. For example, only allow connections from known IP addresses.
• Use Access Control Lists (ACLs): Implement ACLs to define who can use the mail server for relaying. This helps in restricting unauthorized access.
• Regularly Update and Patch: Keep your mail server software up-to-date with the latest patches and updates. This helps in protecting against known vulnerabilities.
• Monitor Server Logs: Regularly monitor your mail server logs for any unusual activity. This can help you identify and address potential issues before they become serious problems.

 

By following these steps, you can ensure that your mail server is not used as an open relay, protecting your server from being exploited by spammers and maintaining the integrity of your email communications.

Understanding TLS and STARTTLS in Email Communication

 

TLS (Transport Layer Security) and its predecessor SSL (Secure Sockets Layer) are cryptographic protocols designed to provide privacy and data integrity between two communicating applications. STARTTLS, on the other hand, is a protocol command used to upgrade an existing, insecure connection to a secure one using TLS. When an email client communicates with an email server, STARTTLS ensures that the connection is encrypted, preventing unauthorized access and eavesdropping. This is crucial for protecting sensitive information transmitted via email, as it helps in maintaining confidentiality and integrity by encrypting the communication channels. Understanding and implementing TLS and STARTTLS in email systems helps organizations and individuals safeguard their email communications against various security threats and vulnerabilities.

How TLS Works in Email

 

• Server-to-Server Encryption: TLS encrypts emails during transmission between servers, ensuring that email content and attachments are protected.
• Client-to-Server Encryption: TLS encrypts the connection between email clients and servers, protecting user credentials and email content from interception on public networks.
• STARTTLS: A protocol command that upgrades an existing insecure connection to a secure one using TLS, enabling encryption on standard email ports without requiring a separate secure port.

 

Importance of TLS and STARTTLS

 

• Security: Prevents unauthorized access to email content during transmission.
• Privacy: Ensures that email contents remain private and unreadable to third parties.
• Authentication: Verifies that emails are sent to the correct server, reducing the risk of man-in-the-middle attacks.

 

Best Practices for Using TLS and STARTTLS

 

• Enforce TLS on Email Servers: Require TLS for all email connections and use trusted certificates.
• Support Opportunistic TLS and STARTTLS: Prefer and enforce STARTTLS on standard ports to upgrade connections to secure ones.
• Use Modern TLS Versions: Ensure the use of TLS 1.2 or higher and disable outdated protocols.
• Configure SMTPS and IMAPS: Use port 465 for SMTPS (SMTP over TLS) and port 993 for IMAPS (IMAP over TLS) for secure email transmission and retrieval.

 

Feedback Loops

 

What are Feedback Loops?

 

Feedback loops in email are tools that help senders know how their emails are being received. When someone marks an email as spam or unwanted, the email service provider sends a report back to the sender. This report tells the sender about the complaint and includes details like the recipient's email address and the original message. These feedback loops help senders identify problems with their email campaigns and make improvements. By understanding why emails are being marked as spam, senders can adjust their content and sending practices to better meet recipients' needs.

Importantly, when someone marks an email as spam, they should be immediately removed from your email list, and you should stop sending them emails. This not only respects the recipient's preferences but also helps maintain a good sender reputation and improves the chances of your emails being delivered successfully to those who want to receive them.

Which ISPs Have Feedback loops and where do I Sign Up For Them?

 

Many major Internet Service Providers (ISPs) offer feedback loops (FBLs) to help email senders manage spam complaints and improve their email practices. Below are some ISPs that offer feedback loops and information on how to sign up for them:

ISPs Offering Feedback Loops

 

• AOL, Yahoo, Verizon - Sign-Up for AOL Postmaster Feedback Loop
• Comcast, BlueTie, Fastmail, Gandi.net, Italiaonline, Libero Mail, Virgilo, Laposte.net, Liberty Global, Unitymedia, UPC, Locaweb, Mail.ru, OpenSRS, Rackspace Technology, Seznam.cz, SFR, SilverSky, Swisscom, Synacor, TIM, Telenet, telenor, Telstra, Terra, UOL, Virgin Media, Ziggo - Sign Up at Return Path (Validity)
• Gmail - Sign-Up for Gmail Postmaster Tools
• Earthlink - Send an email to fblrequest@abuse.earthlink.net with a subject of "feedback loop request" that provides the following information: Company name and contact information, Contact email address, Email address that spam complaints should be sent to, IP addresses to register with one IP address or CIDR denoted range of IP addresses per line,Type of business (ISP, ESP, Web Host, etc.)
• Microsoft (Outlook.com, Hotmail, Live.com, MSN) - Sign-Up for Microsoft JMRP (Junk Email Reporting Program)
• Zoho - Sign-Up for Zoho Mail Feedback Loop

 

Example of an ARF Report:

From: abuse-report@example.com
To: abuse@example.net
Subject: [Abuse Report] Spam from example.com
Content-Type: multipart/report; report-type=feedback-report; boundary="boundary-example-1"

--boundary-example-1
Content-Type: text/plain

This is a report of email abuse. Below is the original message and the machine-readable abuse report.

--boundary-example-1
Content-Type: message/feedback-report

Feedback-Type: abuse
User-Agent: SomeUserAgent/1.0
Version: 0.1
Original-Mail-From: spamsender@example.com
Arrival-Date: Mon, 16 Jul 2023 16:02:43 +0000
Reported-Domain: example.com
Received-Date: Mon, 16 Jul 2023 16:02:43 +0000
Source-IP: 192.0.2.1
Authentication-Results: mail.example.com; spf=fail smtp.mailfrom=spamsender@example.com; dkim=fail (signature did not verify) header.d=example.com; dmarc=fail action=none header.from=example.com

--boundary-example-1
Content-Type: message/rfc822
Content-Disposition: inline

Return-Path: <spamsender@example.com>
Received: from example.com (example.com [192.0.2.1])
by mail.example.net with ESMTP id x50sm4189569pfb.16
for
; Mon, 16 Jul 2023 16:02:43 +0000 (UTC)
Received-SPF: fail (example.com: domain of spamsender@example.com does not designate 192.0.2.1 as permitted sender) client-ip=192.0.2.1;
Authentication-Results: mail.example.net; spf=fail smtp.mailfrom=spamsender@example.com; dkim=fail (signature did not verify) header.d=example.com; dmarc=fail action=none header.from=example.com
Message-ID:
Subject: Special Offer Just For You!
From: "Spammer"
To: user@example.net
Content-Type: text/plain; charset="UTF-8"
MIME-Version: 1.0

[Original message content here]

--boundary-example-1--


 

For more information, you can refer to the official ARF specification: RFC 6449

 

Reputation Management

 

Monitoring email reputation is essential to ensure your emails are trusted and effectively reach your recipients' inboxes. To monitor your email reputation, regularly check feedback from recipients and email service providers. This includes keeping an eye on bounce rates, spam complaints, and unsubscribe requests. Utilize tools and services that provide insights into your sender reputation and email deliverability. Pay attention to metrics such as open rates and engagement levels, as these can indicate how your emails are being received. Additionally, make sure your email practices adhere to best practices and industry standards to maintain a positive reputation. By actively monitoring and adjusting your email strategies based on feedback and performance data, you can improve your email reputation and ensure successful communication with your audience.

Tools for Email Reputation Management

 

• Sender Score: Provides a score that reflects your email sending reputation.
• Google Postmaster Tools: Offers insights into your domain’s performance on Gmail.
• Microsoft SNDS (Smart Network Data Services): Provides data on your IP’s reputation with Microsoft email services.
• Cisco Talos: Provides reputation data for IPs and domains.
• Yahoo Senders Hub: Provides delivery and performance feeds (Yahoo, Aol, Verizon).

 

Blacklist Monitoring

 

Blacklist monitoring for email is a crucial practice for maintaining the health and deliverability of your email campaigns. It involves two primary methods: Below are some ISPs that offer feedback loops and information on how to sign up for them:

• Regular Checking of Blacklists: - This method involves regularly checking your sending IP addresses or domains against popular email blacklists, either manually or using automated tools. Automated monitoring is particularly efficient, as it continuously checks your status and provides real-time alerts if any issues arise, allowing you to quickly investigate and resolve blacklisting problems.
• Monitoring Bounce Backs: - This method involves analyzing bounce back messages from your email campaigns. These messages often contain information indicating if your IP or domain is on a blacklist. By regularly reviewing and analyzing bounce backs, you can swiftly identify and address blacklisting issues.

 

Both methods are essential for ensuring your emails reach your intended recipients' inboxes and maintaining the effectiveness of your email marketing strategies.

 

Popular Public Blacklist

 

• Spamhaus: One of the most respected and widely used blacklists, Spamhaus tracks IP addresses and domains involved in sending spam, phishing emails, and other malicious activities. They maintain several lists, including the Spamhaus Block List (SBL) and the Exploits Block List (XBL).
• Barracuda Reputation Block List: Managed by Barracuda Networks, this blacklist tracks IP addresses that have been reported for sending spam. It is widely used by Barracuda's email security solutions.
• SpamCop: A blacklist that tracks IP addresses reported for sending spam. SpamCop relies on user reports and automated systems to identify and list spam sources.
• UCEPROTECT: This blacklist is known for its aggressive listing policies. It includes three levels (Level 1, Level 2, and Level 3) that escalate based on the severity and frequency of spam detected from an IP address or range of IP addresses.
• Invaluement: Invaluement maintains multiple blacklists focusing on IP addresses and domains involved in sending low-volume spam, snowshoe spam, and other unwanted emails. Their lists include ivmSIP (IP addresses) and ivmSIP/24 (IP address ranges).
• DNSBL: A generic term for Domain Name System-based Blackhole List, which includes various blacklists maintained by different organizations. DNSBLs use DNS to publish lists of IP addresses involved in sending spam.
• Hostkarma: This blacklist categorizes IP addresses based on their email sending behavior, with separate lists for good and bad senders. Hostkarma tracks IP addresses involved in spam, phishing, and other email abuses.
• Proofpoint: Proofpoint operates its own set of blacklists as part of its comprehensive email security solutions. They track IP addresses and domains involved in spam, phishing, and other malicious activities, and their blacklists are used to enhance the security and deliverability of emails for their clients.
• Cloudmark Sender Intelligence (CSI): Cloudmark maintains a reputation-based blacklist that evaluates the sending behavior of IP addresses and domains. Their system uses advanced algorithms and crowd-sourced data to identify sources of spam and other unwanted emails.
• Abusix: Abusix provides comprehensive threat intelligence, including blacklists for IP addresses and domains involved in spam, malware distribution, phishing, and other malicious activities. Their blacklists are widely used by email service providers and security solutions to enhance email deliverability and protect against threats.
• URIBL: URIBL focuses on blacklisting domains that are found in the body of spam emails. It helps to block emails containing links to malicious or spammy websites. URIBL is often used in conjunction with other blacklists to provide a more comprehensive defense against spam and phishing attacks.
• Spam Eating Monkey: SEM maintains several blacklists that focus on identifying IP addresses and domains associated with spam and other unwanted email behaviors. Their blacklists are used by various email service providers to enhance email filtering and deliverability.
• Mailspike: Mailspike provides real-time blacklists that include both IP addresses and domains involved in spam and other malicious email activities. They offer two main lists: the Mailspike Blacklist (BL) for IP addresses and the Mailspike Zero Hour Reputation List (ZRD) for domains.

 

Blacklist Monitoring Services

 

Blacklist monitoring services are essential tools for maintaining the health and deliverability of your email campaigns. These services help ensure that your email sending IP addresses and domains are not listed on any blacklists, which could otherwise lead to your emails being marked as spam or rejected by email servers. By using blacklist monitoring services, you can receive real-time alerts, investigate any blacklisting issues, and take corrective actions to delist your IPs or domains.

• Hetrix Tools: Uptime Monitor & Blacklist Monitor.
• MX Toolbox: One of the oldest DNS toolsets on the internet.
• Easy Dmarc: Monitor Your Reputation on Email Blacklists.
• RBL Tracker: RBLTracker provides easy-to-use, real-time blacklist monitoring, for your email, website, and social media.
• Blacklist Master: 96 RBL's Monitored - Comes with a free trial.
• Power DMARC: Monitor Your Domains, Emails, IPv4 and IPv6 Addresses in 200+ Real-time DNS Blacklists.
• Website Pluse: 82 Different Blacklists, Detail Reports, and up to a 30 minute frequency.
• Rackaid: Checks major DNS blacklist services 24/7 and notify you instantly if your server’s IP address appears in a list.
• eMail Deliveryability Test: Inbox Placement Testing.
• Kickbox: Protect your sender reputation using Kickbox’s comprehensive domain and ip blocklists monitoring tool. Be alerted of issues instantly so you can take action and mitigate damage to your email program.
• MonSpark: Protect your website's SEO and reputation by keeping track of potential blacklistings and taking proactive measures.
• Mailgun: Stay off blocklists, avoid spam traps, monitor your domain and IP reputation, and more with Mailgun Optimize..
• Blacklist Scan: Our DNSBL blacklist monitoring service enables you to monitor all your IPs or URLs against DNSBL blacklists and send you alerts periodically to give you that piece of mind you need. Either monthly or weekly depending on how often you choose.

 

Email Blacklist Checker Tools

 

These tools perform swift, manual scans across multiple public blacklists to determine if a particular email address or domain is listed, which could indicate potential issues with email delivery.

• MultiRBL: Checks multiple blacklists for email addresses and domains. This one is our favorite for a quick fast scan.
• BlacklistAlert.org: A dedicated service for checking email blacklists.
• MXToolbox: Provides a comprehensive email blacklist check along with other diagnostic tools.
• DNSBL.info: Aggregates results from various blacklists into one comprehensive report.
• HetrixTools: Offers blacklist monitoring with quick lookup features.
• WhatIsMyIPAddress: Includes an email blacklist check among its IP and email tools.

 

Blacklist Removal Locations

 

Blacklist removal for email is a critical process for maintaining the deliverability and reputation of your email campaigns. When an IP address or domain gets listed on a blacklist, it means that emails sent from that source are more likely to be flagged as spam or rejected outright by recipient servers. To begin the removal process, you must first identify the specific blacklist that includes your IP or domain. Next, investigate the reason for the listing, which could range from spam complaints to suspicious sending patterns. Once the issue is identified, take corrective actions such as improving email content, ensuring compliance with CAN-SPAM regulations, and implementing double opt-in procedures. After making these adjustments, submit a delisting request to the blacklist administrator, providing evidence of the changes made. Consistently monitoring email performance and maintaining best practices in email hygiene are essential to prevent future blacklisting and to ensure high deliverability rates.

• Backscatterer
• Barracuda
• Cloudmark
• Cyren
• Free.fr
• FortiGuard
• GoDaddy
• Hertzner
• Hotmail
• iCorp
• Invaluement
• McAfee
• Proofpoint
• Spamcop
• Spamhaus
• SpamRATS
• Sophos
• SonicWall
• SURBL
• Talos
• Trend Micro
• UCEPROTECT
• United Online
• Symantec
• WIFI4INDIA
• Yahoo/AOL/Verizon

 

Email Whitelisting

 

Email whitelisting is a process used to ensure that certain email addresses or domains are marked as trusted, allowing their emails to bypass spam filters and be delivered directly to the recipient's inbox.

Below is a list of places to request whitelisting:

• (CSA) Certified Senders Alliance: The CSA acts as a neutral interface between mailbox providers and senders of commercial emails
• DNSWL: Whitelist based on SPFBL
• ISIPP: Offers email accreditation and certification services to help ensure emails are delivered to the inbox.
• Return Path: Provides certification to improve email deliverability rates by ensuring your emails reach the inbox.
• Unitied Online: NetZero, Juno, and Bluelight

 

IP Addresses (Shared, Dedicated, Warming)

 

Shared vs Dedicated

 

Shared IPs are used by multiple senders, pooling their email sending activities together. This means the reputation of the shared IP is influenced by the combined actions of all its users. While shared IPs are managed by email service providers (ESPs) to maintain a good reputation, individual senders have less control over the IP's overall reputation. Shared IPs are ideal for smaller senders or those with lower email volumes, as the reputation management and warming up are handled by the ESP.

Dedicated IPs, on the other hand, are used exclusively by a single sender. This gives the sender full control over the IP's reputation, as it is solely affected by their email sending practices. Dedicated IPs are recommended for larger senders or those with high email volumes, as they provide better deliverability and reputation management tailored to their specific needs.

IP Warmup

 

IP warmup primarily applies to dedicated IPs, especially those that have been used recently but are now starting a new sending pattern. When a dedicated IP is new or has been dormant, it lacks a sending history, making it essential to gradually increase the email volume to build a positive reputation. This process involves starting with a low volume of emails sent to the most engaged recipients and slowly ramping up the volume over time. This gradual increase helps to establish trust with ESPs and ISPs, demonstrating that the sender follows good email practices and is not a spammer. Without proper warmup, emails from a dedicated IP are more likely to be flagged as spam, resulting in poor deliverability and potentially damaging the sender's reputation.

Warming up IP's is not a simple as it seems, you probably seen a lot of charts that say double everyday. Well this is simply untrue, we warmed up 100's of IPs. A lot goes into warming up IP's correctly for good delivery, a simple mistake can cost you months of reputational repair.

Follow the steps below:

• Segment your list: Send to highly engaged users are users that have recently clicked, subscribed, and opened your emails. If you don't know who your active users are, use a service that can tell you which users have been engaging with their emails recently.
• Start Small: You may think 100 emails a day is small, it's not. Check the Major ISP warmup chart below.
• Ramp Slowly: It's a painful process, that you have to wait close to a month to start sending at larger volume. But It's even a more painful process starting over on new IP's.
• Use a warmup service: If you don't want to manage it yourself, let someone else manage it for you.

 

Major ISP Warming Guide:

 

Email Compliance Laws

 

Email compliance laws vary by country and region, reflecting differing approaches to regulating email marketing, protecting consumer privacy, and combating spam. Here are some of the key email compliance laws in different countries:

United States: CAN-SPAM Act

 

• Overview: The CAN-SPAM Act (Controlling the Assault of Non-Solicited Pornography And Marketing Act) was enacted in 2003.
• Requirements:
  • Emails must not use false or misleading header information.
  • Subject lines must accurately reflect the content of the email.
  • The email must include a clear and conspicuous disclosure that it is an advertisement.
  • The email must include a valid physical postal address of the sender.
  • Recipients must be given an opt-out method, and requests must be honored within 10 business days.
• Penalties: Violations can result in fines of up to $43,280 per email.
• Link: CAN-SPAM Act Compliance Guide

 

European Union: GDPR and ePrivacy Directive

 

• Overview: The General Data Protection Regulation (GDPR) and the ePrivacy Directive regulate email marketing within the EU.
• Requirements:
  • Consent must be obtained before sending marketing emails.
  • Senders must provide clear and simple opt-out mechanisms.
  • Personal data must be processed lawfully, fairly, and transparently.
  • Data subjects have rights to access, rectify, and erase their personal data.
• Penalties: Violations can result in fines of up to €20 million or 4% of annual global turnover, whichever is higher.
• Link: General Data Protection Regulation (GDPR)

 

Canada: CASL

 

• Overview: The Canada Anti-Spam Legislation (CASL) is a law designed to protect Canadians from spam, malware, and other digital threats while ensuring businesses can still compete globally. It applies to all organizations that send commercial electronic messages (CEMs) to or from Canada.
• Requirements:
  • Senders must obtain explicit or implied consent before sending emails.
  • Emails must contain the sender's identification information and a method for recipients to withdraw consent (unsubscribe).
  • Consent must be verifiable.
• Penalties: Violations can result in fines of up to $1 million per violation for individuals and $10 million for businesses.
• Link: Canadian Anti-Spam Legislation (CASL)

 

Australia: Spam Act 2003

 

• Overview: The Spam Act 2003 regulates commercial email and other types of commercial electronic messaging in Australia.
• Requirements:
  • Consent must be obtained before sending commercial emails.
  • Emails must include accurate sender identification and contact information.
  • Emails must include a functional unsubscribe mechanism.
• Penalties: Violations can result in fines of up to AUD $2.1 million per day.
• Link: Australian Spam Act 2003

 

United Kingdom: Privacy and Electronic Communications Regulations (PECR)

 

• Overview: PECR complements the GDPR and regulates electronic communications in the UK.
• Requirements:
  • Consent must be obtained before sending direct marketing emails.
  • Senders must provide clear identification and contact details.
  • Recipients must be given a clear opt-out option in every marketing message.
• Penalties: Violations can result in fines of up to £500,000.
• Link: Privacy and Electronic Communications Regulations (PECR)

 

WHOIS Privacy

 

What is WHOIS?

 

WHOIS is a protocol and database system used to look up information about the ownership and registration of domain names. When you perform a WHOIS lookup, you can retrieve details such as the domain registrant's contact information, the registration and expiration dates of the domain, the name servers used, and the registrar through which the domain was registered.

Key Aspects of WHOIS:

 

• Registrant Information: Includes the name, address, phone number, and email address of the domain owner. This information is essential for transparency and accountability on the internet.
• Administrative and Technical Contacts: These are the individuals or organizations responsible for administrative and technical aspects of the domain. Their contact information is also listed.
• Registrar Information: Identifies the company through which the domain was registered.
• Name Servers: Lists the servers that are authoritative for the domain, which play a crucial role in directing internet traffic to the correct location.
• Registration Dates: Provides the creation date of the domain, the last update date, and the expiration date. This information helps determine the domain's age and when it might need to be renewed.

 

Example of a WHOIS Record:

Domain Name: EXAMPLE.COM
Registry Domain ID: 123456789-DOMAIN
Registrar WHOIS Server: whois.example-registrar.com
Registrar URL: http://www.example-registrar.com
Updated Date: 2023-01-01T12:00:00Z
Creation Date: 2020-01-01T12:00:00Z
Registrar Registration Expiration Date: 2025-01-01T12:00:00Z
Registrar: Example Registrar, Inc.
Registrar IANA ID: 1234
Registrar Abuse Contact Email: abuse@example-registrar.com
Registrar Abuse Contact Phone: +1.234567890
Domain Status: ok
Registrant Name: John Doe
Registrant Organization: Example Organization
Registrant Street: 123 Example Street
Registrant City: Example City
Registrant State/Province: EX
Registrant Postal Code: 12345
Registrant Country: US
Registrant Phone: +1.234567890
Registrant Email: john.doe@example.com
Admin Name: John Doe
Admin Organization: Example Organization
Admin Street: 123 Example Street
Admin City: Example City
Admin State/Province: EX
Admin Postal Code: 12345
Admin Country: US
Admin Phone: +1.234567890
Admin Email: john.doe@example.com
Tech Name: John Doe
Tech Organization: Example Organization
Tech Street: 123 Example Street
Tech City: Example City
Tech State/Province: EX
Tech Postal Code: 12345
Tech Country: US
Tech Phone: +1.234567890
Tech Email: john.doe@example.com
Name Server: NS1.EXAMPLE.COM
Name Server: NS2.EXAMPLE.COM
DNSSEC: unsigned


 

Emailing Domain

 

When a domain is used for emailing, the WHOIS information can provide critical insights into the email sender's legitimacy. For example, a reputable organization will often have their WHOIS information publicly available and accurately filled out. Conversely, spammers and malicious actors might hide their identity using WHOIS privacy protection services.

Importance of WHOIS for Email Domains:

 

• Trust and Verification: Email recipients and email service providers (ESPs) can use WHOIS information to verify the legitimacy of the sending domain. Domains with accurate and transparent WHOIS information are more likely to be trusted.
• Troubleshooting and Abuse Management: If issues arise with email delivery or if spam complaints are made, the WHOIS information can be used to contact the domain owner or administrator to resolve the problems.
• Compliance and Legal: Some regulations and compliance frameworks require accurate WHOIS information to ensure accountability and traceability.
• Email Authentication: WHOIS data, in conjunction with email authentication protocols like SPF, DKIM, and DMARC, enhances the overall security and reliability of email communications. Properly configured WHOIS information, along with these protocols, helps prevent email spoofing and phishing attacks.

 

Performing a WHOIS Lookup

 

You can perform a WHOIS lookup through various online tools and services, such as:

• ICANN WHOIS
• DomainTools
• GoDaddy WHOIS
• Network Solutions WHOIS

 

These services provide easy access to WHOIS information, helping you verify domain ownership and obtain other critical details about the domain used for emailing.

 

BIMI Record

 

BIMI, short for Brand Indicators for Message Identification, is an emerging email authentication standard that allows organizations to display their brand logos next to authenticated email messages in recipients' inboxes. This initiative aims to enhance email security, increase brand recognition, and boost customer trust.

What is BIMI?

 

BIMI is a specification that leverages existing email authentication protocols, such as DMARC (Domain-based Message Authentication, Reporting, and Conformance), SPF (Sender Policy Framework), and DKIM (DomainKeys Identified Mail). By meeting these authentication requirements, organizations can use BIMI to display their verified brand logo in the inboxes of participating email providers.

Key Benefits of BIMI

 

• Enhanced Brand Recognition: BIMI allows companies to present their brand logo directly in the recipient's inbox, making it easier for users to identify legitimate emails from trusted brands. This visibility can increase brand recognition and recall.
• Increased Email Security: BIMI helps in combating phishing attacks by ensuring that only authenticated emails from verified sources display the brand logo. This makes it harder for malicious actors to impersonate legitimate brands.
• Improved Customer Trust: By displaying a verified logo, brands can signal to their customers that the email is genuine and trustworthy, leading to higher engagement rates and improved customer confidence.
• Consistency Across Platforms: With BIMI, brands can maintain consistent visual identity across different email clients and devices, providing a uniform experience for recipients.

 

How Does BIMI Work?

 

To implement BIMI, organizations need to follow these steps:

• Email Authentication: Ensure that your domain is authenticated using DMARC, SPF, and DKIM. A DMARC policy of "quarantine" or "reject" is necessary for BIMI implementation.
• Create a BIMI-Ready Logo: Prepare a brand logo in SVG format that meets BIMI specifications. The logo should be square and visually clear at smaller sizes.
• Obtain a Trademark or Wordmark: In order to get a VMC Certificate you need a registered trademark of the logo or wordmark.
• Get a Verified Mark Certificate (VMC): A VMC is issued by a certification authority and confirms the authenticity of your brand logo. This step may involve a validation process to verify the brand's identity.
• DigiCert - DigiCert is one of the leading providers of VMCs. They offer comprehensive validation services to ensure your brand's logo can be displayed in email clients that support BIMI.
• Entrust - Entrust is another major provider offering VMCs. They provide services to help brands authenticate their logos and enhance email security.
• Publish BIMI DNS Record: Add a BIMI record to your domain's DNS. This record includes the location of your logo file and VMC.
• Monitor and Adjust: Regularly monitor your email authentication reports and adjust your BIMI setup as needed to ensure continued compliance and effectiveness.

 

Here is an example of a BIMI DNS TXT record:

 

For more information, you can refer to the official BIMI specification.

 

Important Email Headers

 

To improve email deliverability and enhance user experience, certain optional headers can be very effective. Here are three important optional email headers: List-Unsubscribe, Precedence, and X-Priority.

1. List-Unsubscribe Header

 

Purpose: Allows recipients to easily unsubscribe from mailing lists.

 

Example:

 

Importance: Reduces the likelihood of your emails being marked as spam by providing a clear and easy way to unsubscribe. It can improve the reputation of your sending domain and make it more likely that your emails are delivered to the inbox.

 

2. Precedence Header

 

Purpose: Indicates the priority of the email, commonly used in automated or bulk email systems.

 

Example:

Precedence: bulk

 

Importance: Helps distinguish between different types of emails, such as transactional or bulk. It can help mail servers and clients handle your emails more appropriately, reducing the risk of important emails being treated as spam.

 

3. X-Priority Header

 

Purpose: Sets the priority of the email.

 

Example:

X-Priority: 3 (Normal)

 

Importance: Indicates the urgency of the email to recipients and email clients. Emails with higher priority might be displayed more prominently or flagged differently in some email clients.

 

Example of Enhanced Email Headers in Use

 

Here’s how these headers might look in an email:

From: John Doe <john.doe@example.com>
To: Jane Smith <jane.smith@example.com>
Subject: Your Invoice for June 2024
List-Unsubscribe: <mailto:unsubscribe@example.com>, <https://example.com/unsubscribe>
Precedence: bulk
X-Priority: 3 (Normal)


 

Email Content, Structure, Design

All the technical setup steps discussed earlier are generally one-time tasks. Once you've properly configured your email with the correct settings, you typically won't need to repeat these steps unless you change your domain, ESP provider, or IPs. However, your email content and design are constantly evolving elements. There are numerous factors to consider when creating emails, and these aspects play a crucial role in building a strong email reputation and ensuring your messages reach the inbox.

When creating email content and design to ensure deliverability, there are several important factors to consider. Here are the key aspects you need to be aware of:

 

General Content Guidelines

 

• Avoid Control Characters: Remove control and non-printable characters that can trigger spam filters or disrupt formatting.
• Preheader Text: Use engaging preheader text that complements the subject line and encourages the recipient to open the email. This text is often the first thing recipients see after the subject line in their inbox.
• Replace Non-ASCII Characters: Replace non-ASCII characters with their ASCII equivalents to avoid rendering issues and prevent emails from being flagged as spam by certain filters.
• Spam Keywords: Avoid using words commonly flagged as spam. In order to get a VMC Certificate, you need a registered trademark of the logo or wordmark.
• Text to Image Ratios: Having too many images without enough text can trigger spam filters and cause the email to be flagged as spam.
• Text to Link Ratios: Optimize your email campaigns with the proper balance of text and links.
• Link Verification: Ensure all links are secure (use HTTPS), working, and not listed on blacklists.
• Testing and Previews: Test your emails across different email clients and devices to ensure consistent rendering. Tools that provide inbox previews can help identify and correct issues before sending.

 

CSS Optimizations

 

• CSS Inlining: Use inline CSS to ensure compatibility across different email clients.
• Inherited CSS Removal: Remove redundant inherited CSS to streamline your email's HTML, which can improve load times and reduce the chances of being flagged by spam filters.
• CSS Classes and ID Removal: Removing unneeded classes and IDs reduces the size of your emails and improves your chances of not triggering a spam filter.
• Font Colors: Avoid using bright or flashy colors like red and green, as they can trigger spam filters. Also, avoid using white text on a light-colored background or over an image to ensure readability and avoid spam classification.
• Font Sizes: Using extremely small fonts or extremely large fonts can trigger spam filters, as it is a common tactic used by spammers to avoid detection.

 

Image Management

 

• CDN Management: Host on a reliable Content Delivery Network (CDN).
• Image ALT Tags: Add alt and title attributes to images to improve accessibility and provide context when images do not load.
• Oversized Images: Optimize images by resizing them appropriately, improving email load times.
• Remove Background Images: Removing background images increases email client compatibility over 10%.

 

HTML Optimization

 

• HTML Sanitization: Ensure your email code is safe, secure, and free from potentially harmful elements, enhancing deliverability and protecting recipients.
• Title Attributes: Ensure that your email hyperlinks have descriptive and engaging titles, improving user experience and boosting click-through rates.

 

User Acquisition

 

User acquisition is the process of attracting and converting individuals into customers or users of a product or service. This involves a variety of strategies and tactics aimed at reaching potential users, engaging them with compelling content and offers, and guiding them through the conversion funnel to take a desired action, such as signing up for a service, downloading an app, or making a purchase.

Effective user acquisition requires a deep understanding of the target audience, leveraging channels like social media, search engine marketing, email campaigns, and partnerships to reach them. Additionally, optimizing the user experience and continuously analyzing performance metrics are crucial to refining acquisition strategies and achieving sustainable growth.

Obtain Consent-Based Leads

 

Obtaining consent-based leads is crucial for building a high-quality email list and ensuring compliance with legal regulations.

Steps to contain consent based leads:

 

• Double Opt-In: Implementing a double opt-in process ensures that users who subscribe to your emails genuinely want to receive them. After a user signs up, send a confirmation email with a link they must click to verify their subscription. This confirms the validity of the email address and the user's intent.
• Terms of Service and Privacy Policy: During the signup process, require users to check a box indicating that they have read and agree to your Terms of Service and Privacy Policy. This ensures that users are aware of how their data will be used and provides legal protection for your business.
• Clear Communication: Clearly inform users what type of content they will receive, how often they will receive it, and the benefits of subscribing. Transparency builds trust and sets the right expectations.
• Easy Unsubscribe Option: Always include a clear and easy-to-find unsubscribe link in your emails. Make the process simple and quick, ensuring that users can opt-out without difficulty. This helps reduce spam complaints and maintains a positive sender reputation.

 

Verifying Email Addresses

 

Verifiying email addresses is a critical step in ensuring the quality of your email list and improving deliverability. Here’s how and where you should verify email addresses as part of your user acquisition strategy:

 

Where to Validate Email Addresses:

 

• Sign-Up Form: Verify email addresses at the point of entry on your sign-up form. Implement real-time validation to check for syntax errors, domain validity, and catch temporary or disposable email addresses. This prevents invalid emails from entering your list right from the start.
• Double Opt-In Process: After a user signs up, send a confirmation email with a link they must click to verify their subscription. This step ensures the email address is valid and that the user has access to it.
• Old Inactive Lists: When reactivating old lists, validate all email addresses before sending any campaigns. This helps you avoid high bounce rates and potential damage to your sender reputation.
• Re-Engagement Campaigns: Before sending re-engagement emails to inactive users, verify their email addresses. This ensures that your efforts are directed towards valid contacts and helps improve the success of your re-engagement campaigns.
• Ongoing List Usage: If you regularly send emails to your list and actively monitor engagement, deploy proper segmentation, and you're using bounce management software which every ESP provides, your list is self verifying on every send.

 

Tools to Verify Email Addresses:

 

• Bouncer: Bouncer is an email verification tool that ensures your emails reach real, valid recipients.
• NeverBounce: A service that offers real-time email verification and list cleaning to ensure your emails reach valid addresses.
• BriteVerify: Provides quick and accurate email verification to improve deliverability and reduce bounce rates.
• Hunter: An email verification tool that checks the validity of email addresses and helps you maintain a clean list.
• Kickbox: Verifies email addresses to ensure they are valid and deliverable, helping you reduce bounce rates and improve email performance.

 

Mailstreams

 

Mailstreams are different categories of emails that a company sends, like marketing emails, transactional emails (such as order confirmations), and notification emails (like password resets). Separating mailstreams ensures better email delivery since different types of emails get different reactions from people. If marketing emails receive poor reactions, it won’t affect the delivery of other types, like important order confirmations. It also helps in managing reputation because email providers, such as Gmail or Yahoo, track how good your emails are. Separating mailstreams ensures that complaints about marketing emails don’t harm the reputation of your transactional emails. Additionally, it makes problem-solving easier; if there’s an issue, like high bounce rates, it’s easier to find and fix it when different types of emails are sent separately.

Different Types of Mail Streams

 

1. Transactional Emails

 

These are automated emails triggered by a user's action on a website or app. They typically include:

 

• Order Confirmation: Sent after a purchase is made.
• Shipping Notification: Sent when an order is shipped.
• Password Reset: Sent when a user requests to reset their password.
• Account Creation: Sent after a new account is created.

 

2. Marketing Emails

 

These are sent to promote products, services, or events and can include:

 

• Promotional Emails: Highlight sales, discounts, or new products.
• Newsletter Emails: Provide updates, articles, or curated content.
• Re-engagement Emails: Target inactive users to bring them back.
• Event Invitations: Promote webinars, conferences, or product launches.
• Affiliate Emails: Promote partner products or services, often with special tracking links to credit the affiliate for any sales generated.

 

3. Informational Emails

 

These provide information without a sales pitch, often sent by organizations to their subscribers or members:

 

• Company Announcements: News about company updates, changes, or achievements.
• Product Updates: Information on new features or changes in products or services.
• Industry News: Relevant news and updates about the industry.

 

4. Personal Emails

 

These are one-to-one emails sent from one individual to another, often for personal or professional communication:

 

• Personal Correspondence: Emails between friends or family members.
• Professional Correspondence: Emails between colleagues, clients, or business partners.

 

5. Automated Emails

 

These are sent based on specific triggers or schedules and can overlap with transactional and marketing emails:

 

• Welcome Emails: Sent to new subscribers or customers.
• Onboarding Emails: Guide new users through the initial steps of using a product or service.
• Reminder Emails: Remind users of upcoming events, deadlines, or tasks.
• Feedback Requests: Ask for user feedback or reviews after a purchase or interaction.

 

6. Nurture Emails

 

These are part of a series designed to build relationships with prospects and guide them through the sales funnel:

 

• Educational Content: Provide valuable information and resources.
• Case Studies: Showcase successful use cases or testimonials.
• Follow-Up Emails: Continue engagement after an initial contact or action.

 

7. Internal Emails

 

These are sent within an organization for communication among employees:

 

• Team Updates: Information about project status, team achievements, or internal news.
• Policy Announcements: Updates on company policies, procedures, or guidelines.
• Meeting Invitations: Details about upcoming meetings, including agenda and location.

 

8. Cold Emails

 

These are unsolicited emails sent to potential customers or contacts who have not previously interacted with the sender:

 

• Sales Pitches: Introduce products or services to new prospects.
• Networking Emails: Reach out to potential business partners or collaborators.

 

9. Follow-Up Emails

 

These are sent after an initial email or interaction to maintain communication:

 

• Thank You Emails: Express gratitude after a meeting, purchase, or event.
• Reminder Emails: Follow up on previous communications or pending actions.
• Check-In Emails: Maintain contact with leads or customers to keep the relationship active.

 

How to Seperate Mail Streams

 

To separate mailstreams, you should use a different subdomains, IPs, and DomainKeys Identified Mail (DKIM) for each type of email.

For Example:

Transactional Emails:

• Subdomain: transactional.example.com
• DKIM Key: A unique selector for this subdomain: _dkim.transactional.example.com
• IP Address: IP addresses dedicated for Transactional Email

 

Marketing Emails:

• Subdomain: marketing.example.com
• DKIM Key: A different unique selector for this subdomain: _dkim.marketing.example.com
• IP Address: IP addresses dedicated for Marketing Email

 

Email Segmentation

 

Email segmentation is the process of dividing your email list into smaller, more targeted groups based on specific criteria. This strategy helps to send more relevant content to subscribers, improving engagement rates and, ultimately, email deliverability. By ensuring that recipients receive content that is tailored to their interests and behaviors, you can reduce unsubscribe rates, minimize spam complaints, and enhance your sender reputation.

Segmentation Improves Delivery

 

• Increased Relevance: Segmented emails are more likely to be relevant to the recipient, leading to higher open and click-through rates.
• Reduced Spam Complaints: Sending targeted content reduces the likelihood of recipients marking your emails as spam.
• Lower Unsubscribe Rates: When emails are tailored to the interests of the recipients, they are less likely to unsubscribe.
• Enhanced Sender Reputation: High engagement rates and low complaint rates improve your sender reputation, leading to better deliverability.

 

How to Segment Your Email List

 

Demographic Segmentation

 

Divide your list based on demographic information such as age, gender, location, and occupation. This allows you to tailor content to specific demographic groups.

Behavioral Segmentation

 

Segment your audience based on their behavior, such as past purchases, browsing history, email engagement (opens, clicks), and website activity. This helps you target users with content that matches their interests and actions.

Psychographic Segmentation

 

Group subscribers based on their interests, values, lifestyle, and personality traits. This can be useful for creating highly personalized content that resonates with specific audience segments.

Engagement-Based Segmentation

 

Identify and separate your highly engaged subscribers from those who are less active. You can send re-engagement campaigns to inactive users and exclusive offers to loyal customers.

Purchase History Segmentation

 

Segment your list based on past purchase behavior. This allows you to send product recommendations, special offers, and personalized promotions to customers who have shown interest in specific products or categories.

Lifecycle Stage Segmentation

 

Target subscribers based on where they are in the customer lifecycle, such as new subscribers, active customers, lapsed customers, or leads. This helps you send relevant messages at each stage of the customer journey.

Best Practices for Effective Segmentation

 

• Use Clean Data: Ensure your email list data is accurate and up-to-date to create effective segments.
• Test and Optimize: Regularly test different segmentation strategies and analyze the results to optimize your approach.
• Personalize Content: Use segmentation to create personalized content that resonates with each group.
• Monitor Engagement: Track the performance of your segmented campaigns and adjust your strategy based on engagement metrics.
• Keep Segments Dynamic: Regularly update and refine your segments to ensure they remain relevant as your audience evolves.

 

By implementing email segmentation, you can improve the relevance and effectiveness of your email campaigns, leading to better engagement rates and enhanced email deliverability.

Pruning Inactive Users

 

Maintaining a healthy email list is crucial for effective email marketing and improved deliverability. One important practice is to prune or remove users who haven't engaged with your emails after a certain period. Here’s how to manage inactive subscribers:

Steps to Prune Inactive Users:

 

• Identify Inactive Users: Use your email marketing platform’s analytics to identify users who haven’t opened or clicked any emails within a specific timeframe (e.g., 6 months).
• Segment Inactive Users: Create a separate segment for these inactive users. This allows you to target them with re-engagement campaigns without affecting the rest of your list.
• Send Re-Engagement Campaigns: Develop a series of re-engagement emails aimed at reactivating these users. Offer special incentives, ask for feedback, or simply remind them of the value they get from your emails.
• Clear Unsubscribe Option: Ensure that your re-engagement emails include an easy-to-find unsubscribe link. This allows uninterested users to opt-out rather than marking your emails as spam, which can harm your sender reputation.
• Monitor Engagement: Track the response to your re-engagement campaigns. Move users who engage back to your active list, and keep those who remain inactive in the inactive segment.
• Final Reminder Email: If there’s still no engagement, send a final reminder email informing them that they will be removed from your list unless they take action. This email can create a sense of urgency.
• Prune Inactive Users: Remove users who remain inactive after the final reminder from your email list. This helps maintain a high-quality list and improves overall engagement rates and deliverability.
• Regular Maintenance: Schedule regular maintenance of your email list to prune inactive users periodically. This keeps your list healthy and ensures better performance of your email campaigns.

 

Benefits of Pruning Inactive Users:

 

• Improved Deliverability: Keeping only engaged users on your list helps improve your sender reputation and deliverability rates.
• Higher Engagement Rates: With a more engaged audience, your open and click-through rates will increase.
• Cost Efficiency: Many email marketing platforms charge based on the size of your list. Removing inactive users can reduce costs.
• Accurate Metrics: Pruning inactive users ensures that your email performance metrics accurately reflect the engagement of your active audience.

 

Postmaster Guidelines

 

Postmaster guidelines are sets of best practices provided by major email service providers (ESPs) like Google, Yahoo, and Microsoft to help senders improve email deliverability and maintain a good sender reputation. These guidelines typically cover aspects such as authentication using SPF, DKIM, and DMARC, managing email lists by ensuring they are up-to-date and obtained through proper opt-in procedures, and monitoring feedback loops to handle complaints and bounces effectively. Adhering to these guidelines is crucial for avoiding spam filters, reducing the risk of being blacklisted, and ensuring that emails reach the recipients' inboxes. ESPs provide these guidelines on their respective postmaster or bulk sender support pages, offering valuable insights into how their specific systems filter and handle incoming emails, thus aiding senders in optimizing their email strategies for better engagement and compliance.

Here's a list of Postmaster Guidelines:

 

Google (Gmail)

• Google Bulk Sender Guidelines
• Google Bulk Sender Guidelines
• Gmail Postmaster Tools

 

Microsoft (Outlook, Hotmail, Live)

• Microsoft Sender Information
• Microsoft Postmaster Services

 

Yahoo Mail

• Yahoo Mail Sender Best Practices
• Yahoo Postmaster

 

AOL Mail

• AOL Postmaster
• AOL Mail Best Practices

 

Comcast

• Comcast Postmaster
• Comcast Error Codes

 

Apple iCloud Mail

• Apple iCloud Mail Postmaster

 

Mail.com

• Mail.com Postmaster

 

Rackspace

• Rackspace Postmaster

 

Cox

• Cox Postmaster

 

Spectrum

• Spectrum Postmaster (Charter)

 

Frequently Asked Questions