telnet 127.0.0.1 1234
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
220 smtp.gmail.com ESMTP x20sm3297437wrg.52 - gsmtp
   
HELP
   
214 2.0.0 https://www.google.com/search?btnI=RFC+5321 x20sm3297437wrg.52 - gsmtp
   
QUIT
   
221 2.0.0 closing connection x20sm3297437wrg.52 - gsmtp
Connection closed by foreign host.