Interactive E-mail Troubleshooter

Step 2: Checking if your ISP is blocking Port 25

The next step in diagnosing e-mail problems is to check if your ISP is blocking Port 25. If you are using Windows, you can do so easily from the Command Interpreter. If you do not know how to launch the Windows Command Interpreter, please watch our Command Interpreter Tutorial (in a new window).

When you do this, a box will pop up, indicating something similar to Microsoft Windows XP [Version 5.1.2600]. You will also see a Command Prompt. Proceed as follows:

1.) Type telnet mail.yourdomainnamehere.com.au 26 (of course substituting your domain where indicated).
2.) Press the Enter key.

Watch for output similar to (indicating a successful connection):

220-alicia.netlogistics.com.au ESMTP Exim 4.52 #1 Sun, 01 Jan 2006 13:25:29 +1100
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.

To view this process visually, please view our Checking Port 26 Tutorial (in a new window).


If you can connect to Port 26 of your mail server via Telnet, then your e-mail client is able to connect to the mail server using Port 26. You will need to adjust your mail configuration to reflect this; please click here to read more on how to do so.

If you are unable to connect to the mail server via telnet on neither Port 25 nor Port 26, please contact technical support at support@netlogistics.com.au, citing that you are unable to connect to both Port 25 and Port 26. You may be instructed by a Support Technician to run further diagnostics.

If you can connect via telnet to port 26, and have reconfigured your e-mail client to utilize Port 26 rather than Port 25, but still cannot send or receive your e-mail, click here.