Hi Shawn,
Thanks for your interest.
It's an Imap account.
I'm not on an exchange server.
I haven't set any rules - the program is in default condition - as installed.
I just followed the wizard to set up the account.

I'm really confused, as I've had the program running all morning and no emails have disappeared today. I purposely read some and left some unread. I've also quit Oulook and restarted, shut down laptop and restarted, and still none have disappeared.
Will keep monitoring and report back.