I use Outlook 2010 on Win 7 and have no problems . May I suggest you check with your ISP to see if the mail problem originates with them. The only time I've had any problems whatsoever...it originated with my ISP and was quickly rectified once I notified them.

This is just my personal experience. Perhaps someone else has another suggestion. I've been using Outlook forever
and will never go elsewhere for an email program. That's how satisfied I am with them. :-)

Anne

Have you tried e-mailing yourself?

I use Microsoft Outlook here at home, and we use Microsoft Outlook at work.

The problem you describe is as Anne suggested -- it's with your Internet Service Provider's mail servers. The only time I (or my husband) received duplicate mail downloads is when we're in Outlook here at home. As soon as I log onto the ISP's mail server (nearly every ISP has a way to log into your mailbox on the web if you're not at home, and you can certainly log in via the web even if you are at home), and start deleting the messages from the server, the problem stops.

At work, I have never, ever received multiple downloads of the same message. I work for the state, and we used to have our own (Microsoft Exchange) mail servers. Now we're part of the statewide e-mail, so the servers are in the Microsoft domain. I was an Exchange administrator when we had our own servers, and I have administrative rights in the Microsoft domain. It's not Outlook that's causing the problem -- it is most definitely your ISP's mail servers.

I dropped MS Outlook a few years ago, along with Internet Explorer - they had so many security holes in it, that I went to Mozilla Firefox and Thunderbird.
Haven't been back since.
DH stuck with MS a little longer, but also got frustrated with it holes and limitations. He also switched.