How To Manually Test Connectivity To IMAP/POP/SMTP Services

This article will show you show to test if your computer can successfully open a connection to our mail servers.

Open a CMD (Windows) or Terminal (Mac) window.

Step 1 – Windows users should run the built in CMD.exe program from the Start button.

Step 2 – Mac users should start the Terminal app from Applications/Utilities.

Windows Users: It should be noted that the telnet application is not automatically enabled in some editions of Windows, so you will have to enable it first.

Click Start.
Click Control Panel.
Click Programs and Features.
Click Turn Windows features on or off.
Select the Telnet Client so that the checkbox is filled.
Click OK.

To test connectivity

Step 3 – Enter the following command, replacing SERVERNAME either with your domain name, or your Home Server name.

telnet SERVERNAME PORT

Step 4 – Replace PORT with

110 – to test POP3 connectivity
143 – to test IMAP connectivity
25 – to test SMTP connectivity (use port 525 to skip the 20-second connection delay)

Testing POP3 or IMAP

e.g. if your Home Server is server.serverguy.com and you wish to test POP3 or IMAP connectivity use port 110 or 143 respectively:

telnet server.serverguy.com 110

You should get a response that ends with

+OK Dovecot ready.

Just type quit and hit to exit.

Testing SMTP

e.g. if your Home Server is server.serverguy.com and you wish to test SMTP connectivity use port 25 or 525. Port 25 will incur a connection delay of around 20 seconds, so use port 525 if you wish.

telnet server.serverguy.com 25

You should get a response that ends with

Escape character is '^]'.
 220-server.serverguy.com ESMTP Exim 4.87 #1 Fri, 15 Jul 2016 10:04:53 +0100
 220-We do not authorize the use of this system to transport unsolicited,
 220 and/or bulk e-mail.

Just type quit and hit to exit.