smtp over starttls

Beware, "\r\n" means the return key right after you issue a command.

C:\>telnet smtp.gmail.com 587

220 mx.google.com ESMTP nh6sm29764930pbc.44

Then input

EHLO\r\n

250-mx.google.com at your service, [114.34.198.249]
250-SIZE 35882577
250-8BITMIME
250-STARTTLS
250 ENHANCEDSTATUSCODES

STARTTLS\r\n

220 2.0.0 Ready to start TLS

And then SSL connect should be established.