I have successfully sent emails in my application using OAuth 1.0a (using Signpost) by constructing an XOAUTH string as described here. The problem is that access tokens expire after an hour and this XOAUTH won't authenticate the user for SMTP server after that.
Is there a way to extend/refresh the access token's lifetime without user's intervention? I know this Android app does that, but how?
I managed to upgrade to OAuth 2.0 (using Scribe) where I'm given a refresh token as well, but it looks like Gmail XOAUTH doesn't support OAuth 2.0 tokens. Does Google provide another way to send emails?