The environ is Exchange 2007 and several users in the field on notebook computers. These users connect to the exchange server via OA. The users are named mytech01 - mytech30 and each has a mailbox.
What is happening is that sometimes, at random times, a user will send an email and it will never show up in the recipients mailbox.
Here's an example: the other day, the client called and mytech27 has sent an email. It never arrived in the recipients mailbox. So, I remoted into mytech27 and made sure the mail was sent and that it showed in the sent folder. It DID show in the sent folder.
I then logged into the mail server and used message tracking to track the message. The message shows that it was sent and delivered to the user. Both users are on the same domain. So, the email was sent, I confirmed that it was sent. The email was delivered per the message tracking, but it was not in the recipients mailbox. I looked in spam, junk, deleted, everywhere and there was no message.
This is random, affects different users, and I can't find out where the lost email is going.
PS: as a test, we are configuring the mail so that when the user sends a message, it goes to a dist group so we can check both mailboxes.