Exchange 2007 - Message to multiple recipients only make it to 1 recipient

Question

Weird problem here. I have 2 users with mailboxes on my Exchange Server 2007. This morning, someone from outside the organization sent both of them an email. Both in the TO field seperated by a semicolon. Only 1 recipient received said email. Here is what I've checked:

1. I checked our spam filter and it showed the message as being delivered to both recipients.
2. I then logged into the Exchange Server and brought up the Queue Viewer but it is empty.
3. Checked the users mailbox for the message in the spam folder, deleted items, and any other folders for the Message. I even checked for it in "Recover Deleted Items". Nothing there.

I went into the EMC and ran the Message Tracking tool. Put in the name of the sender, and of the recipient, and it showed the message. Under the Message Tracking Results, it actually shows it twice. The TIMESTAMP is the same for both instances, but one has an EVENTID of RECEIVE, and the other has an EVENTID of DELIVER. I exported the results to a csv file here: http://dl.dropbox.com/u/10997780/results.csv

I can't see anything wrong honestly. Is there something I'm missing? km@mydomain.com received the message, sp@mydomain.com did not. She has successfully received messages from the same sender today.

Answer 1

The DELIVER event had both users listed, which means it definitely got to the user's mailbox; exchange did its job.

What happened to it from there is anybody's guess, but never rule out the user deleting and purging the message, then forgetting about it (intentionally or unintentionally).