Mail Relay test

rbaca · Joined: 15 Dec 2005 Posts: 15

Running Host Monitor 8.64 on Windows 2003 Server. We have an Exchange 2003 server that hosts mailboxes three hops away from the HM server, through one firewall.

The test is set up to send an email to a remote address and then an automatic forward sends it back to the Exchange server. The test works fine mostly, but once in a while (twice a week) we get a "not delivered" alert and a status of Bad. When we check the Exchange mailbox, the message is there but HM just didn't pick it up. When we restart the HM service, then it will successfully log on to the mailbox and grab the email, and then the status clears to OK.

We have tried troubleshooting all of the networking in between the HM server and Exchange, but everything else is good. Is this a bug?

KS-Soft · Joined: 03 Apr 2002 Posts: 12806 Location: USA

May be time interval is too short (Exchange received e-mail after test is performed)?

Which option do you use?
- Alert when incoming mail server does not receive mail within N sec
- Alert when incoming mail server does not receive mail before next checking cycle

Regards
Alex

rbaca · Joined: 15 Dec 2005 Posts: 15

Set to Alert when incoming mail server does not receive mail before next checking cycle. We have performed some troubleshooting on this, and we do see that the email has made it back to the Exchange mailbox. It's just sitting there but HM does not pick it up for some reason. When we restart the HM service (or in some cases close the console application and then start the application up again) it will then see the email, download it, and change status to Good.

KS-Soft · Joined: 03 Apr 2002 Posts: 12806 Location: USA

Not exactly. When you restart HostMonitor it just removes old e-mail without checking when it was delivered or what exactly test item generated this e-mail...
Could you please send 2 copies of e-mail to support@ks-soft.net (one e-mail that was correctly detected by HostMontor, another one that was ignored)?
Do you have installed some real-time antivirus monitors? May be they modify e-mail body?

Regards
Alex

rbaca · Joined: 15 Dec 2005 Posts: 15

I will send you a copy of the email. Our AV does not modify, but the remote mailer may have something. The email goes through MX Logic, Message Labs, and whatever client AV is running on the remote site. It may take a couple of days to fail.

rbaca · Joined: 15 Dec 2005 Posts: 15

I just sent two emails, one from a good test and one that failed.

KS-Soft · Joined: 03 Apr 2002 Posts: 12806 Location: USA

Looks like one of these e-mails was modified by some 3rd party software, it included 2nd copy of "From", "Sent", "To" and "Subject" fields using TAB character in these lines. This leads to the problem...

Do you know what software modifies e-mails in such way ?
Probably MessageLabs Email Security System? But as I see both e-mails were scanned by this software while extra subject line was added to one of them...

Regards
Alex

rbaca · Joined: 15 Dec 2005 Posts: 15

The one you said was the questionable one was actually the good message. I saved it from Outlook using "Save As" a text file. The second email (bad one) was a copy and paste of the email text.