I have a very strange problem. Sometimes (apparently randomly) Adam will send an email to Bob, Chris, and Doug and only Chris and Doug will get it. This pattern happens for various other combinations too (Bob sending to Adam etc).
Before you jump on this and say ... "ahh this is common... it happens all the time.. welcome to email delivery in 2010". Yes, I know ... I've given up on expecting 100% delivery of email long time ago, but that's over the internet - between company mail servers. But this is not my environment in this question. All these users are on a single Exchange server inside a LAN - no email message ever crosses the internet or is transmitted between servers. There is no anti-spam or anti-virus running on the exchange server. I've never had a single email "lost" on a internal network like that until now. All we have is a single SBS 2003 server with exchange on it and about 30 plainly setup workstations running Outlook 2003/2007 in Exchange mode. Small subset of apparently random users are reporting these email delivery problems at apparently random times. We've had 3 instances from 2 different users so far (that I know of) The messages in question will arrive if resent again. There are no bounce messages or any error messages in the even logs. This is what I've verified so far:
- Users are saying the truth that the email was sent. I went into the Outlook sent item and confirmed that the email message was sent out as they said. I also went into the Outlook of the people who did receive the particular message and it was sitting there.
- For the person who didn't get it, I double checked that they don't have any Rules that may be sorting the message into unexpected places
- We don't have any anti-spam program only the one included with outlook 2003/2007. The junk mail folder is empty
- I verified that the sender used the correct email address by looking at the copy of the sent mail.
I guess my question is:
- How do I fix this?
Or if no one comes up with an answer:
- How do I view a log of every single message the went through the server?
- What should I look for in those logs?
- What other diagnostics can I turn on to trace what happened to the "lost" message?