SMTP Test via Telnet

General Notes

• Telnet Notes

  • c:\> telnet  <enter> (launches Telnet)

  • Microsoft Telnet> ? <enter>  (Telnet command help)

  • Escape character:  CTRL + ]

  • Set Local Echo On - so you can see what you type.  WARNING:  Win2000 & XP has a different command!

    • For Win 2000
      C:\> telnet
      Microsoft Telnet> set local_echo<enter>

    • For XP
      C:\> telnet
      Microsoft Telnet> set localecho<enter>
      Replies: Local echo on

  • SMTP Log Files (default, if you checked logging enabled):

    • Directory
      %windir%\system32\logfiles\W3SVC1
      (I suggest) %windir%\system32\logfiles\SMTPSVC1

• STMP Help

  • Once connected to the SMTP server via Telnet (see below)

    • help <enter>

    • The help is very, very limited (my experience).

Steps to test your SMTP server via Telnet 

• Notes

  • Try testing on the server first.  Firewalls may restrict access from the internet.

• Run Telnet from the command prompt:
  C:\> telnet

• If you are using Win 2000 the enter the following command to see the characters you type:
  If Win2000:  set local_echo<enter>
  If XP:  set localecho

• Note about HostName or Server IP address
  Use the IP address of a Ethernet Cards (c:\> ipconfig /all )
  Note: Look for the property called: IP Address

• Open a connection to the ESMTP Mail Service
  open <IP or hostname> 25
  Ex Response (Win 2000 Server):
  220 <your hostname> Microsoft ESMTP MAIL Service, Version: 5.0.2195.6713 ready at Wed, 18 Jul 2007 10:08:52 -0400

• Send the following SMTP command sequences:

  • helo <IP or hostname> <enter>
    Response: 250 <hostname> Hello <[your IP entry]>

  • mail from: <your email address><enter>
    Response: 250 <email address> ... Sender OK

  • rcpt to: <recipient email address><enter>
    Response: 250 <email address>
    (Note:  if you get a 550 error "Unable to relay for ..." then change your SMTP properties under the "Access" Tab, "Relay" restrictions: check "All except the list below" & check "Allow all computers which successfully authenticate to relay, regardless of the list above"

  • data<enter>
    Response: 354 Start mail input; end with <CRLF>.<CRLF>

  • To: <To display email address><enter>
    From: <From display email address><enter>
    Subject:<Subject line info><enter>
    <Enter body text here>
    <enter>.<enter>    (Note: there is a period between the enter keys.)
    Response: 250 ... Queued mail for delivery

  • quit<enter>
    Response: Service closing ....