I have one user that is having the following issue:
Someone sends her an e-mail from external, she has outlook CLOSED on her machine, opens up webmail and is able to receive the message. She opens up Outlook and the message is gone. Nothing is in her deleted or spam, or junk folders for this message. It happens from a few external senders. That same sender can send the same message to all other users in the org, without this issue. When outlook is open and the user send the message, she never receives it. Exchange 2007 message tracker shows it is delivered to the store, so Outlook is deleting all e-mails form these particular users, without showing it anywhere. This is Outlook 2007.
What I have done:
Checked for any rules regarding this sender that are just client based, there are none (no server ones ether)
Checked the tracking logs on the server - the messages are always delivered to the store.
Uninstalled and reinstalled Office
Uninstalled and reinstalled Antivirus - this is running on the other identical setup machines that are able to receive the e-mails from this outside sender.