topic Re: "552 (Spam Message Rejected ) (failed)" in Email

"552 (Spam Message Rejected ) (failed)"

SupportAtCTi — Tue, 22 Apr 2025 13:37:02 GMT

Hello,

Our customer Adams Estate Agents are replying to emails from customers of yours and recive back rejections. Their mail server reports it received the error "552 (Spam Message Rejected ) (failed)"

Checking at the Govenment email checker https://checkcybersecurity.service.ncsc.gov.uk/email-security-check it has a 100% pass, and at is not blacklisted by any of the site listed here https://mxtoolbox.com/.

What else would cause you to block them?

Thanks in advance

CTi Support

Re: "552 (Spam Message Rejected ) (failed)"

Townman — Tue, 22 Apr 2025 15:27:38 GMT

Hi,

A warm welcome to the forums.

This needs one of the staff members for a formal response - @plusnettony might be around.

In the meantime, contrary to what the Government cyber security page reports, MXtoolbox suggests that the domain does not have a DKIM record published. Reliance will then be placed on the SPF configuration; is the email being sent from a SMTP server in A&A's SPF list?

Re: "552 (Spam Message Rejected ) (failed)"

plusnettony — Wed, 23 Apr 2025 09:59:14 GMT

I think we're going to need the full headers on this - if you can get the end user to contact us with headers/bounces, we'll see what we can do