Sendmail and Exchange

[ManagerJay]

I have a problem which I am not sure how to address, or even solve.

Each evening, all of the open-source servers I maintain send their log files, using sendmail, to my Exchange account. Seemed logical so I can get the log files where ever I am.

Anyway, from one of the servers, I am not receiving the log files, or most messages sent. Using the sendmail command, I see the session start and watch the message transfer from the queue on the computer running sendmail, and see the session started on the Exchange Server. I am seeing the error message I/O error on the sendmail machine. This only happens when using internal addresses (10.129.X.X).

If I change the DNS, and use public IP addresses, everything works fine.

Should I concentrate on sendmail, Exchange or DNS? I am at a complete loss on this one.

Thanks,


Jay

 

[ManagerJay]

I have found a solution which works, and I hope someone else will find this useful.

As it turns out the ISP is performing network upgrades and, apparently, have some routers which are not setup correctly, and are fragmenting packets which should not be. Disabling mtu_path_discovery on the sending server fixed the problem.

Jay