Also, be really careful with your UI. Make it clear to the user that
your app is going to send an email on their behalf. Make sure the
user knows the sender and recipient addresses, and if possible the
message body, and don't send without confirmation. If any user ends
up being surprised by the fact that your app sent mail from them
without their consent, your app will be accused of being malware.
Ironically we go as far as to build the message *in the user's own e-
mail program*, display it to them on the screen and then let them to
click "Send" themselves, and we *still* occasionally get "accused of
being malware".
