Why Are My Emails Going to Gmail Spam?

Henry Timmes Email Deliverability Consultant · Named contributor to RFC 7489 & RFC 9989 (DMARC)

Engagement, complaints, authentication and reputation - what Gmail actually measures, and how to fix it.

The Short Answer

Gmail decides placement largely on recipient engagement and on your domain and IP reputation as measured in Google Postmaster Tools. Mail lands in Gmail spam when engagement is low, complaints are high, authentication is missing, or your reputation in Postmaster Tools has dropped into the medium or low band.

The Usual Causes

Authentication. Gmail requires SPF, DKIM and DMARC for bulk senders. Missing any is a fast track to spam.

Low engagement. Gmail watches opens, replies and whether people fish your mail out of spam. A list that never engages signals unwanted mail.

Complaints. Gmail's threshold is strict - keep the spam-complaint rate under 0.3%, and never let it spike.

Reputation. Google Postmaster Tools shows domain and IP reputation. A slide into “Low” predicts spam placement.

Use Google Postmaster Tools

Verify your domain in Google Postmaster Tools and watch domain reputation, spam rate and authentication results. It is the single best diagnostic for a Gmail problem - it tells you what Google thinks of you, which is the thing that actually decides placement.

Fixing It

Confirm SPF, DKIM and DMARC pass (see authentication), prune non-engagers, make unsubscribe effortless to cut complaints, and rebuild by sending to your most engaged recipients first. Reputation in Postmaster Tools will follow.

Frequently Asked Questions

Why are my emails going to Gmail spam?

What spam complaint rate does Gmail allow?

How do I see my Gmail reputation?