From Google for a recent report of the same/similar issue:

If you tried configuring your SMTP server on port 465 (with SSL) and port 587 (with TLS), but are still having trouble sending mail, try configuring your SMTP to use port 25 (with SSL).

https://productforums.google.com/forum/#!topic/gmail/Tv0WGHSleZY


"I'm the one that has to die when it's time for me to die, so let me live my life, the way I want to."
-- Jimi Hendrix