Submit a ticketCall us

Solarwinds & Cisco Live! Barcelona
Join us from the 29th of January to the 2nd of February at Cisco Live 2018 in Barcelona, where we will continue to show how monitoring the network with SolarWinds will keep you ahead of the game. At our booth (WEP 1A), we will demonstrate how SolarWinds network solutions can help. As a bonus, we are also hosting a pre-event webinar - Blame the Network, Hybrid IT Edition with our SolarWinds Head Geek™, Patrick Hubbard on January 24th - GMT (UTC+0): 10:00 a.m. to 11:00 a.m. There's still time to RSVP.

Home > Success Center > Network Performance Monitor (NPM) > Test SMTP server connectivity via telnet

Test SMTP server connectivity via telnet



If Orion alerts are functioning properly and the logs show that a message was sent to the SMTP server, but you didn't receive the expected email, you may need to troubleshoot connectivity between Orion and your SMTP server.



All NPM versions




If a user is not getting email and you want to test the SMTP server, you can use telnet to send a test email. This will verify connectivity to the SMTP server from the Orion server.


Important Note: This test must be performed on the Orion server experiencing the issue. It is not a valid test to perform from your workstation or PC.

Blue text indicates a command you will type in. 
Red italics indicates a key press


1. First, check if telnet is installed:

a. Start > Run > CMD > telnet <smtp-server> <port> <enter>

                  Example:  telnet 25 <enter>


If telnet is not installed, you will get something like this:



2. To install Telnet, please refer to Microsoft website. 


a. Start > Run > CMD <enter>

b.pkgmgr /iu:"TelnetClient" <enter>




If telnet IS installed, you will get something like this after entering the above command (telnet 25):



3. Type the following to send a test email:

  • ehlo me and press <enter>
  • mail from: <sender-email> <enter>
  • rcpt to: <recipient-email> <enter>
  • data <enter>
    • test_smtp_server_7.png
    • subject: Test 123 <enter>
    • <enter>
    • Hi there, this is a test <enter>
    • Finally, to finish the email, type a period (.) and <enter>
      • test_smtp_server_9.png
      • You should get a 250 OK - that means it was successful 
      • If you do not get a 250 OK, and get something else, refer to this guide:
        • This indicates the issue is likely on the SMTP server (likely not running an open relay or the user doesn't have a mailbox)
  • The recipient should then receive an email:



  • If you don't receive the email, contact your SMTP server administrator. 
  • If you do receive the email, you have eliminated connectivity to the SMTP server as a problem. 


Here's the full conversation for reference:







Keywords:  orion npm email alert action smtp server e-mail address fails sent received send 


Last modified