Mac Mail Crazy Problem

I am having a strange problem with Mail. I have two accounts on my Blackberry and Mail, a work account and personal Gmail address. The problem is:

1. I will send an email with my work account to a list of people including my Gmail account on Mail
2. When I check my Gmail account on my Blackberry, it will show the message being sent up to 5, 6, 7 times, but then on a friend's Gmail account in a browser it will have shown up once.

Additionally, I had drafted a short email, then decided not to send and deleted it (I did NOT send it). Shortly after I checked my Blackberry and I had 8 emails in my Gmail account all with one of the words from the email, in 8 separate messages.

This is highly embarrassing if the same 8 messages went out to the list I was sending it to. Any thoughts on what the problem is? Is it Mail or Blackberry?