I have a user that is receiving the following message whenever he sends mail to a particular domain.
I've checked and I'm not on any RBLs. Is there anywhere I can look to get a better idea of what the problem is?
This is the mail system at host server.domain.com
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<email@example.com>: lost connection with mail.domain2.com[aa.bb.cc.dd] while
receiving the initial server greeting