使用 Telnet SMTP 來寄信

如何使用 Telnet 來測試 SMTP 通訊 - Microsoft
Telnet - SMTP Commands (sending mail using telnet)
RFC 821 Mail
RFC 821
RFC 1821

$ telnet
$ set localecho
$ open mailserver.hostname 25
220 mailserver.hostname Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959 ready at  Wed, 15 Jul 2009 15:12:59 +0800

$ HELO mailserver.hostname
250 mailserver.hostname Hello [192.168.0.1]

$ MAIL FROM:solnone@mailserver.hostname
250 2.1.0 solnone@mailserver.hostname....Sender OK

$ RCPT TO:solnone NOTIFY=success,failure
250 2.1.5 solnone@mailserver.hostname

$ DATA
354 Start mail input; end with .
Subject: Test Mail use telnet

Just test.
.

250 2.6.0 ... Queued mail for delivery

$ QUIT