Telnet to test SMTP

Since I wrote up testing pop3 with telnet, I thought I would also write about how you can test SMTP with telnet.

From a command line in windows:


open IPofSmtpServer 25

220 mail.server.domain Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959 ready at . . . .


( is the FROM domain)

250 OK


250 2.1.0 . . .Sender OK


250 OK –


354 Start mail input; end with <CRLF>.<CRLF>

Subject: The Subject of the message.

Press enter TWICE.

The body of the message goes here.

Press enter.

Enter a single period (.) and press enter once more.

250 2.6.0 <………………….> Queued mail for delivery


221 2.0.0 Service closing transmission channel


Lots more SMTP info.

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