Good day! Could you help me please. There is a trouble with delivering e-mails to our clients, they do not receive our letters because the system returns them back. We c… (read more)
Good day! Could you help me please. There is a trouble with delivering e-mails to our clients, they do not receive our letters because the system returns them back. We cannot understand the reasons. The thing is that it does not happen with each letter. It works in a spontaneous way, some letter can be sent without any problem, another one will be returned.
That is what we get from the system:
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
sergeevvrob@mail.ru
host mxs.mail.ru [217.69.139.150]
SMTP error from remote mail server after end of data:
550 Message was not accepted -- invalid mailbox. Local mailbox sergeevvrob@mail.ru is unavailable:
user not found
Reporting-MTA: dns; cpanel9.c.fozzy.com
Action: failed
Final-Recipient: rfc822;sergeevvrob@mail.ru
Status: 5.0.0
Remote-MTA: dns; mxs.mail.ru
Diagnostic-Code: smtp; 550 Message was not accepted -- invalid mailbox. Local mailbox sergeevvrob@mail.ru is unavailable: user not found