Some of my customers on either EC2 or Lightsail with their own (validated and secure) email servers are experiencing this problem, which started yesterday:-
An error occurred while trying to deliver the mail to the following recipients:
xxxxxx.xxxxxx@qrcsl.co.uk
Reporting-MTA: dns; a4-25.smtp-out.eu-west-1.amazonses.com
Action: failed
Final-Recipient: rfc822; xxxx.xxxxxxx@qrcsl.co.uk
Diagnostic-Code: smtp; 554 5.7.1 Service unavailable; Client host [54.240.4.25] blocked using cbl.abuseat.org
Status: 5.7.1
The email servers have SPF, DKIM, DMARC and MTA-STS set up and have been fine for many years.
The IP address 54.240.4.25 is ofcourse one of AWS' SES servers.
I have sent a tweet to AWS and they redirected me here.
Can anyone help?
Regards,
Paul Littlefield
This is a problem that only cbl.abuseat.org can solve. Have you contacted them? You can file a support ticket to ask if AWS is working with them on a systemic problem (like blocking all Amazon IP ranges).