Lost Connection Error Message

[bhickey]

I have a user that is receiving the following message whenever he sends mail to a particular domain.

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

<brad.jones@domain2.com>: lost connection with mail.domain2.com[aa.bb.cc.dd] while
    receiving the initial server greeting

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?

[Goonsniper]

I have a user that is receiving the following message whenever he sends mail to a particular domain.

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

<brad.jones@domain2.com>: lost connection with mail.domain2.com[aa.bb.cc.dd] while
    receiving the initial server greeting

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?

Hi

I'm seeing the same problems with one domain (netsolmail.net).

I've messed with the postfix master.cf file trying to turn on esmtp for that domain but it didn't change the problem.

[bhickey]

Yeah, it's a bit odd. Thus far I've only experienced with a single domain. However, I've been told that they're receiving mail from other senders.

[Goonsniper]

I've started using a smart relay for my outgoing mail and those emails that were previously failing are working fine now. So, I'm going to assume it's something with postfix (I'm sending out through a Cisco Ironport appliance now).

[bhickey]

I wish I knew where to look for the problem.