I've run into an Outlook problem in Windows. It is downloading 2 each of all emails, and for the life of me I cannot figure out what the problem is. Microsoft did an update and manage to screw it up a bit; got that worked out and then the double emails started. Don't know if the timing is coincidental or not. Any thoughts on this would be appreciated.
What kind of account is it configured for? POP, IMAP, Exchange?
If it's IMAP, try this:
Uncheck the "Leave Messages on the Server" box. To do this, click on Tools>Accounts. You will see a box open (named Internet Accounts), click "Mail" tab, click on the mail account, click on Properties>Advanced. Remove the check in the box "Leave a copy of messages on server."
If it's Exchange, talk to your IT crew.
If it's POP? You might have something corrupt in your mailbox or your also downloading mail to a handheld or something. I'd first try recreating the account in your mail client.
It is POP3. All I did was go into accounts and correct the Microsoft issue created when they updated. I unchecked the TTL Security option which doesn't fly on our mail server. I went 587 out port and check My Server Requires authentication. This should not have caused that issue, but maybe something else has corrupted. There's nothing hung in the Outbox. Really strange.