The SMTP server requires a secure connection or the client was not authenticated. The server respon
The SMTP server requires a secure
connection or the client was not
authenticated.
The server response was: 5.7.0
Authentication Required.
Learn more at
to solve above issue try to login on gmail account & click on below link
https://www.google.com/settings/secur...
OR
https://myaccount.google.com/lesssecu...
and after
set = Allow less secure apps: ON
try to re send, here your issue will be solved