Hi, I have a ISPConfig server with a few domains. One client domain have a error to send emails to some providers. (from my ispconfig to anothers mail servers) host said: 550 5.7.1 Access to [email protected] not allowed (in reply to RCPT TO command) BUT, to some few providers, works. The Mx entry points to mail.example.com, and mail.example.com points A to my ISPConfig server. I have configured DMARC, DKIM and SPF and reverse IP. No blacklisted in any list. Can someone help me ?
though everything you have setup and IP is not blacklist, your server IP or that particular domain is blocked at the recipient's email server. Did you try to send from different domain and IP? You have to find out the exact issue and as per that you have to run to the recipient server administrator if its in your hand.
Works from another domain in the same ISPConfig server. Strange thats was working before the client come to us, but not now.
So basically that's the domain/email address which is blocked to recipient end. In this case, you cannot do anything with your server(Since already you have setup everything). You or your client or end client of your client can contact to the recipient server administrator get the things unblocked.