Using Telnet to send mail (By SMTP)

You : telnet 25
Server : Trying ???.???.???.???...
Connected to
Escape character is '^]'.
220 ESMTP Sendmail ?version-number?;
You : Helo
Server : 250 mail.domain.ext
You : mail from
Server : 250 ok
You : rcpt to:
Server : 250 ok

To start composing the message issue the command data
You: data
You : Subject:-type subject here-
then press enter twice
You may now proceed to type the body of your message
To tell the mail server that you have completed the message enter a single "." on a line on it's own.
Server : 250 ok ???????? Message accepted for delivery
You can close the connection by issuing the QUIT command.
You : QUIT