I had the same problem. Although GAE supports 'reply_to' its not implemented in web2py.
I inserted two lines in web2py/gluon/tools.py; here is what the code looks like now: elif self.settings.server == 'gae': xcc = dict() if cc: xcc['cc'] = cc if bcc: xcc['bcc'] = bcc if reply_to: xcc['reply_to'] = reply_to The elif is at line 594 in the current version 1.99.7 Seems to work fine now. On Sunday, February 13, 2011 8:56:16 PM UTC-5, Richard Penman wrote: > > I have also experienced problems with the reply to field. Some info here: > http://code.google.com/p/googleappengine/issues/detail?id=2802 > > Also there are the restrictions on who you can set as the sender which you > probably already know about: > http://code.google.com/appengine/docs/python/mail/sendingmail.html >