Checking Port 25 Is Not Blocked

Port 25 is a standard port used for sending email between mail servers. In some network environments, this port may be blocked by Internet Service Providers or local network configurations to reduce spam or restrict outgoing mail traffic.

This article explains how to check if Port 25 is blocked on your connection and outlines the steps you can take to identify and verify port accessibility for email sending issues.

Refer to the Email Hosting getting started guide for email setup.

 

Check Your Email Settings

 

Check That Port 25 Is Not Blocked

Some Internet Service Providers (ISPs) may block the normal sendmail port 25, so the easiest way is to contact them and ask for the Outgoing Server SMTP setting which you will then replace (Outgoing Server: mail.yourdomain.com) with the above.

Alternatively if your ISP is blocking port 25 you can try port 465 or 587 instead of 25.

Here is a simple test you can find out if this is the case.

 

Please note that on newer versions of Windows, Telnet is not enabled automatically. You can turn on Telnet in your computer's Control Panel by clicking on Programs and Features, then clicking on Turn Windows features on or off and ticking the box next to Telnet.

 

1. Windows users can access this via start > run > cmd. Mac users can use the Terminal application.
2. Enter telnet mail.domain.com 25 (replace domain.com with your own domain name).

If you just see a blank screen then your ISP provider is blocking port 25.

 

If you log in to your Webmail, you will be able to send and receive email from anywhere in the world.