How to Fix Gmail Error 4.7.28 (Unusual Rate of Unsolicited Mail)

By Sparkforge Support Team ·Last reviewed May 3, 2026

Gmail error 4.7.28 is a temporary rate limit triggered by a sending spike or low engagement, not a permanent IP block. Reduce volume to Gmail addresses, send only to engaged contacts, and Gmail typically lifts the throttle within 24-72 hours.

If your Sparkforge campaigns hit this Gmail rejection, the message is throttled — not blocked. Gmail's automated systems are deferring mail from your IP because the recent volume or engagement pattern looked unusual.

4.7.28 Gmail has detected an unusual rate of unsolicited mail originating from your IP

Is your IP blocked?

No. The 4.x.x code means Gmail is deferring email, not rejecting it permanently.

No manual delisting request is needed.
Gmail removes the restriction automatically once sending behavior improves.
Your sender reputation, balance, and templates stay intact.

Why this happens

The 4.7.28 throttle usually fires for one of these reasons:

A sudden volume spike to @gmail.com and @googlemail.com addresses.
Sending from a new or recently warmed IP before reputation is established.
Campaigns sent to inactive, unengaged, or purchased lists.
Workflows or automations re-sending to the same contacts too frequently.
Above-average spam complaints or low open rates.
SPF, DKIM, or DMARC misalignment.

Even legitimate senders can trip this when volume ramps too fast.

How to fix it

1. Cut sending volume to Gmail

Temporarily reduce mail to Gmail addresses.
Ramp volume gradually instead of large bursts.

2. Send only to engaged contacts

Target users who opened or clicked recently.
Cut old, inactive, and purchased lists from the audience.

3. Audit automations

Check workflows that may loop or fire too often.
Pause campaigns that caused the spike until volume normalizes.

How long until it clears?

Gmail typically lifts the rate limit within 24-72 hours once sending stabilizes. Continuing to send only to engaged contacts and following bulk-sender best practices speeds recovery.

Frequently Asked Questions

Does Gmail 4.7.28 mean my IP is blacklisted?

No. It is a temporary rate limit from Gmail's spam-protection systems, not a blacklist entry. Gmail lifts it automatically when sending behavior improves.

Do I need to file a delisting request?

No. There is no manual delisting for 4.7.28. Gmail removes the throttle on its own once volume and engagement signals normalize.

How long does recovery usually take?

In most cases Gmail lifts the restriction within 24 to 72 hours. Continued good sending hygiene shortens the recovery window.

What single change has the biggest impact?

Cutting volume to Gmail addresses and sending only to recently engaged contacts. The throttle is driven by complaint and engagement signals more than raw volume.

Will SPF, DKIM, or DMARC misalignment cause this?

Yes, authentication problems can contribute. Verify all three pass for your sending domain before resuming normal volume.