Server error 452

[#1]

Every message I try to send through plusnet this morning (using either email client - Outlook on one computer and Thunderbird on another - or from plusnet webmail) gets this response:

Server error: '452 <xxxxxx@xxxxc> recipient rejected - too many recipient in last hour'

There seem to be other similar errors reported in this forum, but we've only sent about five emails this morning - ALL rejected, so it's ludicrous that the system thinks this is "too many". Is it possible that my account has been hacked by some bot and is generating spam emails by the million? How could I find out?

[#2]

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@simonc2 wrote:

Is it possible that my account has been hacked by some bot and is generating spam emails by the million?

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 Having dealt with this scenario at many commercial sites, you’d be inundated by the number of emails returned as undeliverable. On average about 6,000 messages an hour.

[#3]

Many thanks for that insight. I assume it's a plusnet generated problem then. Any idea what could be causing it?

[#4]

There’s many posts on the forum citing similar problems to yours. Best to wait for someone  more knowledgeable  to reply.

[#5]

This issue has been escalated, I will give it another prod.

It helps to know the minute of the hour that the issue was encountered ... and to know if just after the top of the hour, one is able to send again.

[#6]

Hi @Townman

Thanks for your attention. 

We had Undeliverable messages this morning at 10:23 10:26 and 10:44 and two or three notifications on the plusnet webmail page at around 10:30.

Interestingly I just tried sending from Outlook at 12:01 and that one got through, ie just after the top of the hour. Hope that's helpful.

[#7]

It has just happened to me again here, at 11:46 &11:52. When re-sent at 12:01 they both went ok.

[#8]

@mavison 

it's always comforting to know it's not just me!!!

[#9]

Seems to be gettong more frequent for me.

Tried to send at 13:28, 13:33 & 14:22 all rejected 452..

Tried at 14:29 from android , alse failed but no reason.

[#10]

This is going to be a recurrent issue.

There are various quotas in the system - this one is reset on the hour.  When it is exceeded, no mail can be sent until the top of the current hour.

It has been escalated.

[#11]

Yes ... but my last 4 failures were considerably nearer the start of the the hour than all my previuous failures.

[#12]

Just been on the phone to support.

This issue is with the incident management team ... and is being worked on.

[#13]

Hi Simon,

I am so happy to have discovered this forum and your post regarding the server error 452 whilst randomly searching Google.

This problem first stared happening to me on 26/08/25 and has gradually been getting worse day by day. Originally when I spoke to Plusnet technical support they fobbed me off with one of the usual, "the problem must be at your end, as we don't have anything wrong at our end. They then tried to tell me that I was sending too many emails in an hour, just more of their  usual BS!" I was also advised to delete any emails that were being held on the webmail portal as they tried to suggest that I had exceeded my storage capacity, which it turns out I hadn't. Nevertheless which I did - all 72 of them and initially there was some success.

By 08/09/25 however things were getting worse and even with the webmail portal completely empty I was at crisis point as I had so much work to do and nothing would send. I then phoned Plusnet technical support again and was finally put through to a manager who apparently has opened an investigation and I should get a response early this week. Currently however it appears I am only able to send 1 email every hour. Its just crazy!

Plusnet keep telling me about the Migration to Greenby (which is an additional charge) and that this should resolve the issue. I have therefore requested that rather than wait for an migration email invite, if I could just go ahead and migrate now! They have said they would look into this.

[#14]

Moderator's note:
This thread has been locked as it is a duplicate of ihe topic being actively discussed here:

https://community.plus.net/t5/Email/SMTP-error-452/m-p/2020385#M52737

Please continue this conversation on this linked topic.