Hello, I have a problem with one of my customers who tries to send me emails that mailcow systematically refuses. However, I have no problem with other customers who send me emails without problems.
When email1@clientdomaine.com sends me an email I get this error:
<myemail@domain.com>: host mail.sendemail.fr[75.119.***.**] said: 550 5.1.0
<email1@clientdomaine.com>: Sender address rejected: User unknown in
virtual mailbox table (in reply to RCPT TO command)
Reporting-MTA: dns; smtp-1.jabatus.fr
X-Postfix-Queue-ID: 72B37E01C1
X-Postfix-Sender: rfc822; email1@clientdomaine.com
Arrival-Date: Sun, 21 Jul 2024 14:13:06 +0200 (CEST)
Final-Recipient: rfc822; myemail@domain.com
Original-Recipient: rfc822;myemail@domain.com
Action: failed
Status: 5.1.0
Remote-MTA: dns; mail.sendemail.fr
Diagnosis-Code: smtp; 550 5.1.0 <email1@clientdomaine.com>: Sender
address rejected: User unknown in virtual mailbox table
But when the email client2@clientdomain.com sends me an email I receive it without problems.
I whitelisted my client’s domain in mailcow but I still have this problem.
Mailcow is in version 2024-06c and it is the latest version.
Thank you in advance for your help