can I push 'hanging' sending email in gmail outbox?

I sent out three (big emails - 6 pictures from my mobile camera) very quickly one after each other. Now after 10 or so minutes they are still in the gmail outbox folder. I experienced the same when I was connected via both wireless or mobile network. **Can I somehow push the emails to be sent out?** I tried to open them and send again but it didn't help. Last time this happened I deleted them and sent out slowly one after each other again and it went ok. HTC Desire 2.1