Lewis I am having no luck doing this
First: log into your BIS and create a filter for your gmail account to not forward messages sent from you. That will solve that little annoyance.
Second, not necessary but recommended, log into gmail on a computer and first set up a label, I call mine "BlackBerry". Then make a gmail filter to first archive then label all messages with you as the sent from address. This will keep your web based inbox clean of messages you've sent.
I'm on Tmob 8100 plz