iOS troubleshooting: My iPad is convinced my e-mail password is wrong.

I juggle several e-mail accounts using the stock e-mail app, and while my iPad will download new messages going to that adress, it refuses to send them, saying the username or password is wrong. Same settings on my iPhone, iMac and on the browser for the account and it works perfectly, but I just can't seem to get my iPad to accept this. any ideas here, guys?

I refuse to call tech support because I won't pay for them to do their fvcking jobs.  

Like the person above me suggested check your ingoing and outgoing mail server settings (google your email provider to find the correct addresses). Also, find out whether your SMTP server requires authentication, in which case you have to select that in the settings.