Gmail is becoming more and more popular, and I have been using it more also. I did run into one problem with sending emails from gmail.com, but I found the solution and thought I would post it just in case anyone else is having the same problem.
When you send and email from gmail, and you have enabled the pop account in your gmail settings for outlook and or your blackberry, you will automatically recieve a copy of your email you just sent. This feature is built in to gmail so that you have a record of any sent emails on your computer or phones.
In order to not receive the copy of the sent emails, you will have to go to your outlook and create a rule making any emails received from your email address (email@example.com) is mine so any thing coming from myself to myself is sent directly to my deleted file.
For your Blackberry you will have to go to your carriers blackberry Webclient and make a filter that does not pull any emails from yourself.
You will still get any emails that someone that sends you an email to gmail.