>>285
$ telnet gmail-smtp-in.l.google.com 25 -4
Trying 142.251.2.27...
Connected to gmail-smtp-in.l.google.com.
Escape character is '^]'.
220 mx.google.com ESMTP d2e1a72fcca58-7273c6e825csi8152505b3a.159 - gsmtp