# Campaign Cleaner > Campaign Cleaner is an email HTML optimization platform that automatically scans, cleans, and fixes email campaigns before sending — improving deliverability, inbox placement, and rendering consistency across all major email clients. Campaign Cleaner addresses the technical layer of email marketing: the HTML quality issues, spam signals, and deliverability risks that exist inside the email code itself. It handles 70+ automated fixes including spam score reduction, CSS inlining, image optimization, link safety checks, inbox previews, and preheader management. The platform integrates with major ESPs and supports both one-off campaign scans and API-based automation. ## Core - [Campaign Cleaner - Email HTML Optimization Platform](https://campaigncleaner.com/): Product overview, full feature list, and how Campaign Cleaner improves deliverability by fixing HTML-level issues before sending. - [Pricing](https://campaigncleaner.com/pricing.html): Subscription plans and pricing — no haggle, everyone gets the same rate. - [Integrations](https://campaigncleaner.com/integrations.html): Connect Campaign Cleaner with your ESP, including Mailchimp, Klaviyo, ActiveCampaign, and others. - [Documentation](https://campaigncleaner.com/documentation.html): Technical documentation for using Campaign Cleaner, including API reference and feature guides. - [FAQs](https://campaigncleaner.com/faqs.html): Frequently asked questions about Campaign Cleaner features, pricing, and deliverability. - [Contact](https://campaigncleaner.com/contact.html): Support and contact information. ## Email HTML Optimization Features - [Email Alt Text & Alt Descriptions](https://campaigncleaner.com/alt-descriptions.html): AI-powered generation of missing alt text for email images — improves spam scores and accessibility. - [Background Images in Email](https://campaigncleaner.com/background-images.html): Detection and safe fallback handling for CSS background images that break in Outlook and other clients. - [Blacklisted Link Checker](https://campaigncleaner.com/blacklisted-link-checker.html): Scans every URL in an email against threat databases and blacklists before sending. - [Broken Link Checker](https://campaigncleaner.com/broken-link-checker.html): Finds and flags dead or broken links in email HTML before campaigns go out. - [Email Image CDN Management](https://campaigncleaner.com/cdn-management.html): Migrates email images to a fast, reliable CDN with automatic resizing, format conversion, and hash modification. - [CSS Classes & IDs Removal](https://campaigncleaner.com/classes-and-ids.html): Strips unnecessary CSS classes and IDs from email HTML to reduce code bloat and improve deliverability. - [Control Characters Removal](https://campaigncleaner.com/control-characters.html): Detects and removes invisible control characters that cause rendering issues and can trigger spam filters. - [CSS Inliner for Email](https://campaigncleaner.com/css-inliner.html): Converts stylesheet rules to inline styles for consistent rendering across email clients that strip head CSS. - [Diacritic Character Removal](https://campaigncleaner.com/diacritic-characters.html): Replaces accented and special characters that cause encoding problems across email clients. - [Font Color Adjustment](https://campaigncleaner.com/font-color-adjustment.html): Detects near-invisible text colors that trigger spam filter hidden-text rules and corrects contrast ratios. - [HTML Comments Removal](https://campaigncleaner.com/html-comments.html): Strips HTML comments that inflate email file size and can expose template logic to recipients. - [HTML Minification for Email](https://campaigncleaner.com/html-minification.html): Reduces email HTML file size to stay under Gmail's 102KB clip threshold and improve load times. - [Email HTML Sanitizer](https://campaigncleaner.com/html-sanitizer.html): Removes unsafe or extraneous HTML tags and attributes that cause rendering issues or spam filter penalties. - [Inherited CSS Removal](https://campaigncleaner.com/inherited-css.html): Cleans cascading styles inherited from CMS or design tools that break email rendering. - [Link Title Attributes](https://campaigncleaner.com/link-titles.html): Adds or corrects title attributes on email links for deliverability and accessibility compliance. - [Non-ASCII Character Handling](https://campaigncleaner.com/non-ascii.html): Detects and resolves non-ASCII encoding issues that cause garbled text and deliverability problems. - [Oversized Image Detection](https://campaigncleaner.com/oversized-image-detection.html): Identifies images that are too large for email and automatically downsizes them. - [Poor CDN Quality Detection](https://campaigncleaner.com/poor-cdn-quality.html): Flags images hosted on unreliable or low-reputation CDNs that hurt deliverability and load times. - [Email Preheader Text](https://campaigncleaner.com/pre-header.html): Best practices, ideal length, and tooling for setting effective email preheader preview text. - [SpamAssassin Score Checker](https://campaigncleaner.com/spam-assassin.html): Tests email HTML against SpamAssassin rules and lowers the overall spam score. - [Spam Keyword Triggers Checker](https://campaigncleaner.com/spam-keyword-triggers.html): Analyzes keyword spam ratio and flags high-risk trigger words in email copy. - [Successive Punctuation & CAPS Detection](https://campaigncleaner.com/successive-punctuation.html): Detects excessive punctuation, ALL CAPS, and other formatting patterns that raise spam scores. - [Text-to-Image Ratio](https://campaigncleaner.com/text-to-image-ratio.html): Analyzes and corrects the ratio of text to images to avoid spam filter image-heavy penalties. - [Text-to-Link Ratio](https://campaigncleaner.com/text-to-link-ratio.html): Detects link overload that triggers spam filters and provides ratio guidance. ## Deliverability & Testing Tools - [Inbox Placement Tester](https://campaigncleaner.com/inbox-placement-tester.html): Tests where an email lands — inbox, spam, or promotions tab — across Gmail, Outlook, Yahoo, and more. - [Email Inbox Previews](https://campaigncleaner.com/inbox-previews.html): Renders email screenshots across major clients and devices to catch layout and rendering issues before sending. - [MX Vision - Email List Analyzer](https://campaigncleaner.com/mx-vision.html): Breaks down an email list by mailbox provider (Gmail, Outlook, Yahoo) to identify deliverability risk by segment. - [Email Font Size Guide](https://campaigncleaner.com/email-font-size.html): Recommended font sizes for email on desktop and mobile for readability and spam score safety. ## Guides & Resources - [Email Deliverability Guide 2026](https://campaigncleaner.com/email-deliverability-guide.html): Comprehensive guide covering authentication (SPF, DKIM, DMARC), sender reputation, and inbox placement strategies. - [Email Deliverability Consultant](https://campaigncleaner.com/email-deliverability-consultant.html): When and how to engage a deliverability consultant for Microsoft 365, Gmail, and Yahoo issues. - [Is Email Scraping Legal?](https://campaigncleaner.com/email-extraction-guide.html): Guide to email extraction legality, risks, relevant laws, and ethical list-building alternatives (2026). - [Email Spam Traps Explained](https://campaigncleaner.com/email-spamtrap-guide.html): What spam traps are, how they end up on lists, and how to protect sender reputation (2026). - [AI-Assisted Email Optimization](https://campaigncleaner.com/ai-helper.html): How AI is used to balance text-to-image and text-to-link ratios in email campaigns. - [How to View Email HTML Source](https://campaigncleaner.com/view-email-html-code.html): How to extract and view raw HTML from Gmail, Yahoo, and Outlook email clients. - [Mail Deliverability Test](https://maildeliverabilitytest.com/): Standalone inbox placement test tool for Gmail, Office 365, Yahoo, and more — a companion site by Campaign Cleaner. ## Free Tools - [Mail Tester](https://campaigncleaner.com/tools/mail-tester/): Free email spam and deliverability tester — checks spam score, authentication, and inbox placement signals. - [Preheader Generator](https://campaigncleaner.com/tools/preheader-generator/): Generates hidden preheader HTML for Gmail, Outlook, and Yahoo inbox preview text. - [ISP Email Provider Breakdown](https://campaigncleaner.com/tools/isp-email-provider-breakdown/): Analyzes MX records from an email list to break down subscribers by mailbox provider. - [MX Checker](https://campaigncleaner.com/tools/mx-checker/): Looks up MX records and mail server status for any domain. - [DNS Lookup](https://campaigncleaner.com/tools/dnslookup/): Queries A, MX, TXT, SPF, and DMARC DNS records for any domain. - [Reverse DNS Test](https://campaigncleaner.com/tools/reverse-dns-test/): Verifies FCrDNS and PTR records for email deliverability. - [SPF Lookup](https://campaigncleaner.com/tools/spf-lookup.html): Checks any domain's SPF record instantly. - [SPF Generator](https://campaigncleaner.com/tools/spf-generator.html): Builds a valid SPF TXT record for any domain. - [DKIM Lookup](https://campaigncleaner.com/tools/dkim-lookup.html): Checks any domain's DKIM record by selector. - [DKIM Generator](https://campaigncleaner.com/tools/dkim-generator.html): Generates DKIM keys for a domain. - [DMARC Lookup](https://campaigncleaner.com/tools/dmarc-lookup.html): Checks any domain's DMARC record and policy. - [DMARC Generator](https://campaigncleaner.com/tools/dmarc-generator.html): Builds a valid DMARC TXT record. - [Email Open Rate Calculator](https://campaigncleaner.com/tools/open-rate-calculator.html): Calculates and benchmarks email open rates. - [Email Bounce Rate Calculator](https://campaigncleaner.com/tools/bounce-rate-calculator.html): Tracks hard and soft bounce rates against industry benchmarks. - [Spam Complaint Rate Calculator](https://campaigncleaner.com/tools/spam-complaint-rate-calculator.html): Checks complaint rate against Google and Yahoo sending thresholds. ## Use Cases - [Campaign Cleaner Use Cases](https://campaigncleaner.com/use-cases.html): Real before/after examples of email optimization across industries and sending scenarios. - [Affiliate Marketing Email Optimization](https://campaigncleaner.com/affiliate-marketing-use-case.html): How Campaign Cleaner fixes 70+ issues in affiliate marketing emails to improve deliverability. - [Microsoft Word Email Cleanup](https://campaigncleaner.com/microsoft-word-use-case.html): Cleaning bloated HTML from Word-authored emails for safe, deliverable sending. - [Newsletter Optimization](https://campaigncleaner.com/newsletter-use-case.html): Before/after examples of newsletter HTML cleanup using Campaign Cleaner. ## Comparisons & Alternatives - [Email on Acid Alternative](https://campaigncleaner.com/email-on-acid.html): Why brands switch from Email on Acid to Campaign Cleaner (2026 comparison). - [Litmus Alternative](https://campaigncleaner.com/litmus-email.html): Feature and pricing comparison between Litmus and Campaign Cleaner. - [Best Email Automation Services 2026](https://campaigncleaner.com/best-email-automation-services.html): Top email automation platforms compared by features and deliverability support. - [Best Email Validation Services 2026](https://campaigncleaner.com/best-email-validation-services.html): Bulk email verification and bounce checker services compared. - [Best Email Marketing Services 2026](https://campaigncleaner.com/top-email-marketing-services.html): Top email marketing platforms compared by features, deliverability, and pricing. - [Best Email Service Providers 2026](https://campaigncleaner.com/top-email-service-providers-esp.html): ESP comparison covering features, security, and pricing. - [Best Transactional Email Services 2026](https://campaigncleaner.com/top-transactional-email-services.html): Mailchimp Transactional vs Amazon SES vs SendGrid and 8 more services compared. ## Blog - [Email Spam Words to Remove](https://campaigncleaner.com/blog/spam-keyword-phrases-to-remove.html): List of high-risk spam keyword phrases to eliminate from email copy. - [Remove Email Fingerprints](https://campaigncleaner.com/blog/remove-email-fingerprints.html): What email fingerprints are and how to remove tracking identifiers from email HTML. - [Email Design Mistakes](https://campaigncleaner.com/blog/email-design-mistakes.html): Common email design errors that hurt rendering, deliverability, and engagement. - [How to Boost Email Open Rates](https://campaigncleaner.com/blog/boost-your-email-open-rates.html): Tactics for improving open rates through subject lines, preheaders, and list hygiene. - [Email Deliverability & Open Rates](https://campaigncleaner.com/blog/boosting-email-deliverability-open-rates.html): How deliverability improvements translate to measurable open rate gains. - [Best Fonts for Email Newsletters](https://campaigncleaner.com/blog/best-fonts-email-newsletters.html): Font choices that render reliably across email clients and avoid deliverability issues. - [Email Bot Opens & Clicks](https://campaigncleaner.com/blog/email-bot-opens-clicks.html): How to identify and filter bot-driven open and click data from email analytics. - [Email Compliance Guide](https://campaigncleaner.com/blog/email-compliance.html): CAN-SPAM, GDPR, and CASL compliance requirements for email marketers. - [Single vs Multi-Column Email Newsletters](https://campaigncleaner.com/blog/single-or-multi-column-newsletters.html): Layout comparison for email newsletter design and rendering across clients. - [Email Marketing Automation](https://campaigncleaner.com/blog/email-marketing-automation.html): Automation strategies for triggered and drip email campaigns. - [Gmail Promotions Tab](https://campaigncleaner.com/blog/gmail-promo-tab.html): Why emails land in Gmail's Promotions tab and what can be done about it. - [Email Subject Lines](https://campaigncleaner.com/blog/email-subject-lines.html): Subject line best practices, length, and patterns that improve open rates. - [When to Mark Email Spam vs. Unsubscribe](https://campaigncleaner.com/blog/when-to-mark-email-spam-vs-delete-unsubscribe.html): The difference between spam reports and unsubscribes, and the deliverability impact of each. - [CTA Optimization for Email](https://campaigncleaner.com/blog/cta-boosting-email-conversion-rates.html): How to write and design CTAs that improve click-through and conversion rates in email. - [Email List Building Strategies](https://campaigncleaner.com/blog/email-list-building-strategies-engagement-conversions.html): Ethical list-building methods that attract engaged subscribers. - [Email Marketing Goals](https://campaigncleaner.com/blog/email-marketing-goals.html): How to set measurable goals for email marketing campaigns. - [Email Engagement](https://campaigncleaner.com/blog/email-engagement.html): Engagement metrics, what they mean for deliverability, and how to improve them. - [Why Emails Land in Spam](https://campaigncleaner.com/blog/spam-emails.html): Common causes of spam folder placement and how to fix them (2026). - [Email Marketing Mistakes to Avoid](https://campaigncleaner.com/blog/email-marketing-mistakes.html): 7 costly campaign errors and how to fix them before they damage deliverability. - [Email Mistakes to Avoid When Designing Campaigns](https://campaigncleaner.com/blog/email-mistakes-to-avoid.html): Design-layer mistakes that break rendering and hurt engagement. - [Email Marketing Myths Debunked](https://campaigncleaner.com/blog/email-marketing-myths.html): Common misconceptions about email marketing that cost senders results. - [Email Marketing Advice That Sounds Good But Destroys Results](https://campaigncleaner.com/blog/email-marketing-advice-sounds-smart-terrible-practice.html): Conventional wisdom that actually hurts email performance. - [Email Marketing Challenges in 2026](https://campaigncleaner.com/blog/email-marketing-challenges.html): 10 common problems email marketers face and how to solve them. - [Email Segmentation Strategies](https://campaigncleaner.com/blog/email-segmentation-strategies.html): 13 ways to segment email lists for better engagement and revenue. - [Email Marketing Funnel Tools 2026](https://campaigncleaner.com/blog/email_marketing_funnel_tools.html): 10 best platforms to build and automate email funnels. - [Email Marketing Features That Boost Productivity](https://campaigncleaner.com/blog/email-marketing-feature-productivity.html): Tools and tactics for maximizing email marketing efficiency. - [Free Email Marketing Templates](https://campaigncleaner.com/blog/free-email-templates.html): 12 top resources for free email templates (2026). - [Email Opt-In Form Best Practices](https://campaigncleaner.com/blog/key-elements-high-converting-email-opt-in-forms.html): 13 elements that drive email opt-in conversions (2026). - [Grow Your Email List Without Opt-In Forms](https://campaigncleaner.com/blog/attracting-subscibers-without-opt-in-forms.html): 6 ways to grow an email list using alternative acquisition tactics (2026). - [Lead Generation Tools 2026](https://campaigncleaner.com/blog/lead-generation-tools.html): Expert picks for growing an email list through lead generation. - [Email Marketing Platforms with Advanced Segmentation](https://campaigncleaner.com/blog/marketing-automation-segmentation.html): 18 expert picks for ESP segmentation features (2026). - [Effective Email Marketing Content](https://campaigncleaner.com/blog/effective-email-marketing-content.html): Key factors that drive opens and clicks in email content (2026). - [Email Marketing Tips & Best Practices](https://campaigncleaner.com/blog/email-blogs.html): Expert strategies and best practices for email marketing. - [Gmail Promotions Tab: Triggers and Fixes](https://campaigncleaner.com/blog/gmail-promo-tab.html): Words and tactics that trigger Gmail's Promotions tab, and how to avoid them. - [Marketing Tools You Can't Live Without](https://campaigncleaner.com/blog/marketing-tools-you-cant-live-without.html): Expert recommendations for essential marketing tools (2026). - [Underrated Marketing Tools](https://campaigncleaner.com/blog/underrated-marketing-tools.html): Hidden-gem tools that can transform your marketing strategy. - [Marketing Software with Advanced Analytics](https://campaigncleaner.com/blog/marketing-software-analytics.html): Affiliate marketing software for advanced analytics and reporting. - [Professional Marketing Tips](https://campaigncleaner.com/blog/professional-marketing-advice.html): 18 expert strategies that actually work for marketing professionals (2026). - [Turning Marketing Feedback into Results](https://campaigncleaner.com/blog/marketing-feedback-results.html): 18 marketing stories and how feedback drove measurable improvements. - [How to Build a Brand from Scratch](https://campaigncleaner.com/blog/building-a-brand.html): Expert brand-building strategies for 2026. - [Customer Satisfaction Survey Tools](https://campaigncleaner.com/blog/customer-satisfaction-surveys.html): 10 expert picks for customer satisfaction measurement (2026). - [Which Brands Are Most Trustworthy](https://campaigncleaner.com/blog/trustworthy-brands.html): What earns consumer trust, according to 16 experts. - [Products That Influenced Purchasing Decisions](https://campaigncleaner.com/blog/influencing_purchasing_decisions.html): Products with compelling backstories that drove buying decisions.