topic Re: Unsolicited Rate Limit Error - To Gmail in Email

Unsolicited Rate Limit Error - To Gmail

offscotland — Wed, 30 Sep 2026 11:14:52 GMT

Has anyone come across this error reported by Gmail today 30/09/2026.

Reporting-MTA: dns; gateway1.enmail.co
X-Postfix-Queue-ID: ECB3F46454
X-Postfix-Sender: rfc822; {my email address .....plus.com}
Arrival-Date: Wed, 30 Sep 2026 08:18:25 +0000 (UTC)

Final-Recipient: rfc822; {sending to gmail address}

Original-Recipient: rfc822; {sending to gmail address}
Action: failed
Status: 4.7.28
Remote-MTA: dns; alt1.gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 421-4.7.28 Gmail has detected an unusual rate of mail
    originating from your SPF 421-4.7.28 domain [<xxxxx>.plus.com      35].
    To protect our users from 421-4.7.28 spam, mail sent from your domain has
    been temporarily rate limited. 421-4.7.28 For more information, go to
    421-4.7.28 https://support.google.com/mail/?p=UnsolicitedRateLimitError to
    421 4.7.28 review our Bulk Email Senders Guidelines.
    4fb4d7f45d1cf-6ae16d50391si1239068a12.208 - gsmtp

Three separate emails all bounced....

Re: Unsolicited Rate Limit Error - To Gmail

Townman — Thu, 01 Oct 2026 09:28:56 GMT

This is a question to raise with Greenby.

@plusnettony FYI - does this look like Gmail is already getting snotty with the Greenby gateway subsequent to the migration of relay.plus.net to their proxy?

Re: Unsolicited Rate Limit Error - To Gmail

plusnettony — Thu, 01 Oct 2026 11:23:12 GMT

Possibly, it looks to be checking plus.com again as one email address (If I'm reading it correctly).

I've sent a test message, and I'm just waiting for a bounce.

Re: Unsolicited Rate Limit Error - To Gmail

MisterW — Thu, 01 Oct 2026 11:50:57 GMT

Possibly, it looks to be checking plus.com again as one email address (If I'm reading it correctly).

I can understand(to some extent!) why it did that previously when DKIM was implemented as 'relaxed' on the plus.com domain. However from looking at a test email sent yesterday, both DKIM & SPF are implemented on the <account>.plus.com subdomain, so what earthly reasoning does gmail have for treating everything as coming from the parent domain?

but I guess gmail will do whatever they want to...

Re: Unsolicited Rate Limit Error - To Gmail

jab1 — Thu, 01 Oct 2026 11:53:35 GMT

Wait for Microsoft to re-adopt the same tactics...

Re: Unsolicited Rate Limit Error - To Gmail

MisterW — Thu, 01 Oct 2026 11:57:56 GMT

to answer my own question...

I guess where the parent domain is NOT a TLD , gmail are trying to preclude the trick of using subdomains to get around their rate limiting for a domain.

Re: Unsolicited Rate Limit Error - To Gmail

pvmb — Thu, 01 Oct 2026 12:01:35 GMT

I'm usually the very opposite of a Conspiracy Theorist but...

There has to be some 'rational'(?) explanation for this behaviour. I have noted comments online that this might be construed as a tactic by both Gmail and Microsoft to completely take over the email business. Perhaps it is time for it to be looked into closely at an official level?

Re: Unsolicited Rate Limit Error - To Gmail

jab1 — Thu, 01 Oct 2026 12:02:29 GMT

That idea was mentioned in the earlier 'discussions' on this subject, @pvmb .

Re: Unsolicited Rate Limit Error - To Gmail

Baldrick1 — Thu, 01 Oct 2026 12:11:50 GMT

From: https://support.google.com/mail/answer/81126?visit_id=639264466974178337-3459158831&p=UnsolicitedRateLimitError&rd=1#increase-volume-slowly&zippy=%2Crequirements-for-sending-or-more-messages-per-day

Is:

Starting February 1, 2024, email senders who send more than 5,000 messages per day to Gmail accounts must meet the requirements in this section.

Set up SPF and DKIM email authentication for your domain.
Set up DMARC email authentication for your sending domain. Your DMARC enforcement policy can be set to none.

relevant? Specifically, does Greenby add a DMARC record?

Re: Unsolicited Rate Limit Error - To Gmail

MisterW — Thu, 01 Oct 2026 12:32:42 GMT

relevant? Specifically, does Greenby add a DMARC record?

An <account>.plus.com domain is unlikely to send >5000 messages / day, so it shouldnt apply.

However AFAICS there IS a DMARC record defined for each <account>.plus.com domain.

For info, a test message I sent earlier this morning to a gmail address WAS delivered but marked as Spam.

Re: Unsolicited Rate Limit Error - To Gmail

plusnettony — Thu, 01 Oct 2026 12:36:08 GMT

My test came through as expected albeit delayed. I'll look at some other tests.

Re: Unsolicited Rate Limit Error - To Gmail

Townman — Thu, 01 Oct 2026 12:47:29 GMT

@MisterW / @Baldrick1

I just ran a MXToolBox query on my account.plus.com domain...

There is no sub-domain DMARC record
There is a DMARC record for plus.com
That is reported by PlusNet's DNS service

I have attempted to configure a sub-domain (hosted domain) DMARC record in the Greenby portal following the AI support instructions. The UI does not permit "_dmarc" as a host name. I have an open fault report on the matter.

So from a validation point of view, DMARC remains unaltered.

What does perplex me is that MXToolBox is indicating that the queries are coming from PLUSNET's NS, not Greenby's. A nslookup of the domain reports the NS as "primary name server = ns1.force9.net".

There is DKIM on the subdomain - the MXToolBox query advises that was reported by Greenby's DNS.

Re: Unsolicited Rate Limit Error - To Gmail

MisterW — Thu, 01 Oct 2026 13:01:30 GMT

@Townman

For my <account>.plus.com domain MXtoolbox says there IS a DMARC record

Odd though, mine reports the NS as ns1.plusnet.co.uk ?

Re: Unsolicited Rate Limit Error - To Gmail

Townman — Thu, 01 Oct 2026 13:07:19 GMT

@MisterW

Could this possibly be residual from your account being used as a lab-rat for testing email domain verification options a few years back. Remember you had SPF when others did not.

Re: Unsolicited Rate Limit Error - To Gmail

MisterW — Thu, 01 Oct 2026 13:12:13 GMT

I was just thinking that...

Re: Unsolicited Rate Limit Error - To Gmail

Townman — Thu, 01 Oct 2026 13:38:10 GMT

Your Plusnet email account is not a sound point of reference ...

Re: Unsolicited Rate Limit Error - To Gmail

abitpedantic — Thu, 01 Oct 2026 21:44:05 GMT

I reported this exact issue on here 6 months ago (Problems sending to gmail - Plusnet Community). I don't think anything specific was done and eventually I was able to send to individual gmail addresses again but today the problem has returned. 70 minutes after sending an email I received exactly the same rejection message as @offscotland.