Many E-mail clients and services use port 25 for SMTP to send out E-mails. However an ISP (Internet Service Provider) may block port 25 in order to prevent spamming by its customers. This article will show you how you can check to see if Port 25 is blocked on your network.
- Windows OS:
In order to check if port 25 is blocked, click on the “Start Menu”
Search for “cmd” and press enter to go to "Command Prompt"
In the newly opened command prompt enter the following command followed by “Enter” button:
telnet YourDomain.com 25 - Linux OS:
In order to check if port 25 is blocked, simply open your favorite shell/terminal and type the following command followed by “Enter” button:
telnet YourDomain.com 25 - Apple/Mac OS:
In order to check if port 25 is blocked, navigate to Mac HD -> “Applications” directory -> Utilities sub-directory. Once the terminal is opened type the following command followed by “Enter”:
telnet YourDomain.com 25
If you receive the following result, that means that port 21 is not blocked from your ISP or your Firewall:
Trying 127.0.0.1...
Connected to yourwebsite.com.
Escape character is '^]'.
220 ds6-uk.gigalayer.com ESMTP Exim 4.63 Tue, 24 Jun 2015 13:45:04 -0700Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
telnet: Unable to connect to remote hostThen you should review your firewall or contact your local ISP for further assistance.
This article is provided as a courtesy. Installing, configuring, and troubleshooting third-party applications is outside the scope of support provided by GigaLayer.