I know there are already several threads about this, but I'm not sure what my issue is since I've had this blackberry for almost a year and it just started happening yesterday.
When I send an email from my gmail account using a web browser, that same sent message will then show up on my blackberry. Is there a setting or something that I accidentally changed? I can't think of anything that would make this happen.
It's not anything you changed, but a long awaited backend change on the RIM servers. If you search on the forum (or google) for 2 way gmail sync, you will get lots of discussion about it.