[SOLVED] Issue with DNSBL - Misleading Error Messages

[Gaugamon]

Hello

I am currently exploring Proxmox Mail Gateway and have set up a test system. However, I have encountered an issue that has raised concerns for me.

While testing the Mail Gateway with DNSBL, I observed in the logs that one of my test emails was flagged as spam with the following error message:

postfix/postscreen[879]: NOQUEUE: reject: RCPT from [xxxxxxxxxx]:44165: 550 5.7.1 Service unavailable; client [xxxxxxxxxxx] blocked using dnsbl.sorbs.net; from=<xxxxxxxxxxxxxxx>, to=<xxxxxxxxxxxxxx>, proto=ESMTP, helo=<mail-wm1-f68.google.com>

While the rejection itself is not a problem, the issue arises when the sender receives the following error message:

A message that you sent could not be delivered to one or more of its recipients. This is a permanent error.

The following address failed: test@test.com

SMTP error from remote server for RCPT TO command, host: xxxxxxxxxx (xxxxxxxxxx) reason: 550 Requested action not taken: mailbox unavailable

It's important to note that the email mailbox does exist, and there is no issue with its availability.
The error message may be misleading as it results from the email being flagged as spam via DNSBL.
It is crucial for me that customers are aware their emails might be flagged as spam via DNSBL, and this is not indicative of an actual mailbox issue.

Is there a solution to modify or customize these error messages, or is this something I have to accept?

Thank you for your assistance.

 

[magicpeter]

Das würde mich auch interessieren.

 

[sb-jw]

Error code 550 has several meanings. The question here is, which server sent this message? As a rule, the rejecting server should not do this but the source server, so the problem should theoretically lie on the source server and not on the rejecting PMG.

 

[Gaugamon]

I thought I could make things clearer for the sender, but it doesn't seem like its possible.
But thanks for the reply.

Best regards Gaugamon