You should find that the connection blocks. can be in the port is closed (firewall) or disabled external connections.
I get
220 mx.google.com ESMTP rc10si18057727lbb.160 - gsmtp
Connection success gmail-smtp-in.l.google.com
HELO granin.me
250 mx.google.com at your service
MAIL FROM: <
[email protected]>
250 2.1.0 OK rc10si18057727lbb.160 - gsmtp
RCPT TO: <
[email protected]>
250 2.1.5 OK rc10si18057727lbb.160 - gsmtp
RSET
QUIT
email <
[email protected]> exist!