Dven thoug the configuration was correct:
smtp.gmail.com:465 and with correct user and password, the messages would not go out.
I thought it could be due to one of the several Avast applications I have installed. I stopped VND and Antictrack but still would not work.
I then stopped Avast premium security and it worked.
I have reported de issue to Avast support and will update you accordingly.
