I sent an email to myself a few days ago through the gmail app and it's still sending, anyone know how to make it actually work?
Yes. I usually get this switching ROMs, but I think it's the same deal. I can receive email, but it never sends. Try this:
Scroll down and find/select Gmail-Clear Data
I do the same for Gmail Storage, though this may or may not be necessary. This does reset your settings, but it should work again.