‘telnet’ is not recognized as an internal or external command, operable program or batch file.

When I tried to check the connectivity from SharePoint Server to Exchange server on port 25 via telnet command, I got the following error.

'telnet' is not recognized as an internal or external command, operable program or batch file.

telnet not recognised


The Telnet Client feature was not installed on the server.


To install Telnet Client feature,you should follow the mentioned steps below:

  • Open Server Manager > Manage > Add Roles and Features.


  •  Continue clicking on Next button until reaching to Features section.

before you begin

  • Scroll down until finding Telnet Client > Check it.

telnet feature

  • Click Next > Click Install.

telnet installation progrss

  • Wait until the feature installation has finished > Click close.

Feature installation complete

  • Go back to open the command prompt as administrator > Type the following command.

    telnet [Exchange Server FQDN or IP] [Port] Ex: telnet dc 25

  • If the port is opened, you should get the following that means SharePoint Server can connect to the SMTP server.

telnet connected

  • else you will get the following that mean the specified port is closed, and you could not open connection to the host.

telnet can not connect

In this case,you should check with the System administrator the following points:

  • What’s the IP or FQDN for SMTP Server ?
  • What’s the assigned port for SMTP server ? where the default port is 25.
  • On your server, the ports might be closed by a firewall.thence, you should redefine the inbound and outbound rules related to SMTP.

Enjoy 🙂


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