Emails disappearing at random.

[RTWilke]

I use Apple Mail on my Mac and my email is hosted on an Exchange server.

On a regular basis--multiple times a day--I will receive an email but after I open it, it disappears from my mailbox. It doesn't always happen. Just sometimes. And then, more often than not, it will reappear after a period of time.

During this period it has disappeared, I can access the email via webmail on my Exchange server.

This is driving me crazy! What do I need to do?!

Thanks,

Bob Wilke