So the other day I wrote and email and it tried to send and failed with a temporary server error. Now I can't get it to stop trying to send and it doesn't show up anywhere. I sent it using the email app my stratosphere came with under my gmail account.
Try checking the "Drafts" folder on both your phone and via the web interface for Gmail; if it's in there, you can just delete it.
Failing that, a reboot may clear things out. If not, try clearing the app's cache manually by going in to
Settings->Applications->Manage Applications, touching the
All tab, and scrolling down to the name of your email program. Touch it to call up the app management tools, and then touch the
Clear cache button. DON'T touch the
Clear data button or it will delete all your account settings, too.