How to fix relay access denied error?

Question

PHP

Hello! There are two servers: test ( http://devsn.domain.com) and combat (httpS://sn.domain.com). After the admins messed with the mail server, the Web application stopped sending letters on the production server.
To test on two servers, I did the following steps:
telnet mymailserver.com 25
helo sd.domain.com
mail from:< [email protected] >
rcpt to:< [email protected]
> the server gives an error relay access denied, code 554. But on the test server there is no such error and further steps are successfully completed and the letter safely leaves.
And now the question: Does the error occur on the side of the mail server, or could it be that it occurs from behind the web server? I'm leaning towards the postfix configs (although the recipient is the same, on two servers, one swears and the other doesn't), but I don't have access to the postfix server, so I have to guess. Could it be that the mailer settings do not accept HTTPS? Or if the web server needs to be tuned, could you indicate where to look.
Thanks to all!

Answer 1

cant in postfix. and https has nothing to do with it - mail goes via smtp

Answer 2

The error, as it were, hints that forwarding to this recipient is prohibited. It is possible that the wrong accepted domain is specified in the postfix settings.