Question SMTP Error (550)

[Mustafa Asker]

Everyone can send mail and I can receive any mail. the subscriptions I host on the same server can not send mail to each other. I'm getting the error below.

SMTP Problem (550): "mustafa@exrom.com.tr" recipient could not be added (5.1.1 <mustafa@exrom.com.tr>: Recipient address rejected: User unknown in virtual mailbox table)

 

[Mustafa Asker]

My hosted domains (exrom.net, exrom.com.tr)

info@exrom.net -> send to all e-mail addresses successfully .. x@exrom.com.tr does not send mail to users. I get this error when I press the send key.

SMTP Problem (550): "mustafa@exrom.com.tr" recipient could not be added (5.1.1 <mustafa@exrom.com.tr>: Recipient address rejected: User unknown in virtual mailbox table)