From http://support.microsoft.com/kb/323350…
To test the SMTP service, follow these steps:
- On a computer running Windows Server 2003, type Telnet at a command prompt, and then press ENTER.
- At the telnet prompt, type set LocalEcho, press ENTER, and then type open <machinename> 25, and then press ENTER.The output resembles the following:
220 computername.microsoft.com ESMTP Server (Microsoft Exchange Internet Mail Service 5.5.2651.58) ready
- Type helo me, and then press ENTER.The output resembles the following:
250 OK
- Type mail from:email@domain.com, and then press ENTER.The output resembles the following:
250 OK - mail from <email@domain.com>
- Type rcpt to:youremail@yourdomain.com, and then press ENTER.The output resembles the following:
250 OK - Recipient <youremail@yourdomain.com>
- Type Data, and then press ENTER.The output resembles the following:
354 Send data. End with CRLF.CRLF
- Type Subject:This is a test, and then press ENTER two times.
- Type Testing, and then press ENTER.
- Press ENTER, type a period (.), and then press ENTER.The output resembles the following:
250 OK
- Type quit, and then press ENTER.
The output resembles the following:
221 Closing Port / Mail queued for delivery