The intial telnet: > symbolises your shell prompt.

The empty line between the headers and the body is important, as is the line containing only a full stop at the end of the article body.

telnet: > telnet smtp
telnet: Trying
telnet: Connected to
telnet: Escape character is '^]'.
server: 220 ESMTP server ready Tue, 20 Jan 2004 22:33:36 +0200
client: HELO
server: 250
client: MAIL from: <>
server: 250 Sender <> Ok
client: RCPT to: <>
server: 250 Recipient <> Ok
client: DATA
server: 354 Ok Send data ending with <CRLF>.<CRLF>
client: From:
client: To:
client: Subject: Test message
client: This is a test message.
client: .
server: 250 Message received:
client: QUIT
server: 221 ESMTP server closing connection