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
This problem is a known bug in Android 2.1 (don't know if it is still present in newer versions). There is not much that you can do except being careful not to send too big emails. From my experience, it will eventually be sent but it can take up to a day.
Be careful because it will block all the emails you sent after the large one! It seems they need to be sent in the order they were created.
A solution to this problem is to use the Dropbox application, to upload your pictures to Dropbox, to "long press" on the filename, then "Share..." and "Share a link" by email to your recipients. This will only send a link by email so the message will not block as it does with large files.
I have the same problem, I think also for emails without attachments. The solution is to open the respective email. When I open it (by tapping on it in the Outbox), it gets sent within a few seconds (the caption goes from "Queued" to "Sending" to "Sent" or something like that within seconds).
