552 Spam Message Rejected

[#1]

One of my clients is having a problem emailing me - they are able to reply to my emails without issue, however when composing a new email they recieve the following error and the email is not sent/ I do not recieve the email. 

SMTP error from remote mail server after end of data:

552 Spam Message Rejected

As far as I can tell the email does not contain elements that should flag it as spam, and I've not recieved this problem when dealing with anyone else. I have screenshots of the email and error that may be of use.

I would be very grateful if anyone could offer any assistance.

[#2]

Is your client a user of Plusnet's email services?

If yes, then they should raise the query here.

If no, at what point do they get the message?

• When attempting to send - in which case they need to contact THEIR email provider to determine why THEIR provider is rejecting the message submission
• After the email was sent, it being from one of Plusnet's inbound mail servers - in which case, you will need access to the non-delivery report

"...when composing a new email..."

That very much suggests that the issue is some content in their NEW email signature, which is not present in their REPLY / FORWARD email signature.  Most email applications facilitate using different email signatures (or none) for new / response emails.  Quite often users do not have / use signatures on reply / forwarded emails.

[#3]

Thanks for your response, I will get back to you when I have heard from my client.

[#4]

Hi,

I have seen your PM but the system is not letting me reply...