After receiving a complaint about not receiving mail from an specific sender, while another user account on the same IRedmail server does, I took a look at mail.log and see the following:
Sep 2 03:15:10 mail postfix/smtpd[22517]: warning: xxx.xxx.xx.xxx: hostname xxxxx.xxxxxx.com verification failed: Name or service not known
Sep 2 03:15:11 mail postfix/smtpd[22517]: NOQUEUE: reject: RCPT from unknown[xxx.xxx.xx.xxx]: 550 5.1.1 <[email protected]>: Recipient address rejected: User unknown in local recipient table; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<mail.xxxx.cn>
The other users on this IRedmail server can receive mail from that sender.
Some idea of what is happening with Postfix here ?
Thanks