Re: [otrs] Problems with group of email

But what about the MTA logs? can you see that the email was accepted by the mail server and then sent on to it's next destination? If your MTA has sent it on then it's not your system that is causing the problem but the remote system (in which case poke their postmaster to check their logs to find out why it's not being delivered).

Yeah. At this point, it's not your server.