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SMTP Error Reference

550 5.7.28

Gmail: IP has too many ratings — high complaint or spam-folder rate

Variant of 5.7.28 indicating your IP triggered too many spam-folder placements or user complaints. Distinct from rate-limit — this is a reputation alarm. Pause and remediate.

Last updated: May 23, 2026


Overview

What 550 5.7.28 Means

What it means

Gmail's '5.7.28 ... too many ratings' variant signals that your IP has accumulated too many spam-folder placements or user spam-marks recently. The 'ratings' term is Gmail's internal vocabulary for the per-message classifications their filter assigns. High ratings = high spam classification = throttled or blocked sending.

Who you'll see it from

Gmail consumer accounts and Google Workspace domains. Distinct enough from generic 5.7.28 (rate limit) that the text matters — read it carefully.

Why it happens

Your recent sends have been classified as spam at a high rate. Causes: poor content (spammy language, link density), low engagement (recipients ignoring/deleting), high complaint rate (recipients marking as spam), or sending to a list with low quality (high bounce, low open rates).

Resolution

How to Fix 550 5.7.28

  1. 1

    Stop sending to Gmail

    Each additional message during a high-ratings state adds to the rating count. Pause immediately. Resume only after Postmaster Tools shows reputation recovering.

  2. 2

    Check Gmail Postmaster Tools spam rate

    postmaster.google.com shows your domain's user-reported spam rate, IP reputation, and domain reputation. Anything above 0.1% spam rate triggers throttling. 0.3% triggers severe restrictions. Stay below 0.1%.

  3. 3

    Audit your campaign content for spam triggers

    Use the CAN-SPAM Checker at coldrelay.com/tools/can-spam-checker. Common triggers: spammy subject lines, link-shortener URLs (bit.ly, t.co), all-caps text, excessive exclamation points, HTML/text mismatch, image-only emails, suspicious sender names.

  4. 4

    Reduce send volume by 80%

    Cut Gmail-bound volume to 20% of pre-incident levels. Continue at this reduced volume for 2-4 weeks. Reputation recovers gradually with consistent low-volume, low-complaint sending.

  5. 5

    Verify your unsubscribe mechanism works

    Recipients who can't unsubscribe mark as spam instead. Gmail's Feb 2024 rules require a one-click unsubscribe (List-Unsubscribe header) for bulk senders. Verify your sending platform sets this header correctly.

  6. 6

    Improve list quality before resuming

    Run new lists through email verification. Remove role accounts (info@, sales@, contact@) which frequently mark as spam. Prefer LinkedIn-sourced verified contacts to scraped contacts.

  7. 7

    Consider migrating to fresh infrastructure if reputation is unrecoverable

    If Postmaster Tools shows persistent 'Bad' or 'Low' reputation, recovery may take months. ColdRelay provisions clean dedicated IPs that start neutral. Pair with stricter content and list discipline to avoid recurrence.

Authority

References

Cold email infrastructure

550 5.7.28 in the Cold Email Context

High ratings come from cold email that doesn't engage. The proximate fix is content quality; the structural fix is list quality. ColdRelay can't fix poor content or low-quality lists — but it can give you a clean dedicated IP that builds reputation faithfully when you do everything right. The 2/day/mailbox volume cap exists precisely because higher volumes increase the chance of cumulative ratings damage even with good content. Lower volume per mailbox means lower per-mailbox rating exposure.

FAQ

Frequently Asked Questions

What counts as a 'rating' in Gmail's system?

Each message you send gets classified by Gmail's filter on a continuous scale. Messages classified as likely-spam contribute to your IP/domain's negative ratings. User spam-marks are the strongest negative rating. Repeated negative ratings degrade your reputation.

Is 0.1% spam rate the actual threshold?

Per Gmail's published bulk-sender guidance, yes. Above 0.1% user-reported spam rate, you enter throttling. Above 0.3%, you face severe restrictions. Stay below 0.1% as the operating ceiling.

How long until ratings improve?

Gmail's reputation system has multi-week memory. Improvements (lower volume, better content, list cleanup) start showing in Postmaster Tools within 1-2 weeks. Full recovery from a 'Bad' tier takes 4-12 weeks of consistent good behavior.

Can I appeal high-ratings throttling?

No direct appeal mechanism. The only fix is consistent good behavior that lowers your rating average. Postmaster Tools is the visibility — there's no 'reset reputation' button.

Keep reading

Related SMTP Errors and Guides

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