Can't send email? Is your port 25 blocked? Print

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Can't send email? It's possible that your ISP or computer configuration is blocking the port 25 that is required for sending email, you can check by running the following test...
 
How to Check if Port 25 is Blocked on Your Computer
 
If you are experiencing problems sending mail through then try the following test. This test will determine if your computer's Port 25 is blocked. If the port is blocked and you have not configured a firewall (or some other hardware/software) to block port 25, you will need to contact your ISP to request removal of the block.
 
Launch a telnet application such as Microsoft Windows' Telnet or Mac OS Terminal.
If you are using Microsoft Windows XP or 2000, click on > Run and in the Open field type cmd then click OK.
If you are using Microsoft Windows 98 or Me, click on  > Run and in the Open field type command then click OK.
If you are using a Macintosh OS X system, go into your Applications > Utilities folder and launchTerminal. 
 
Type telnet mail.yourdomain.com 25 then press the enter/return key. (replace your actual domain for yourdomain.com)
 
You should see something similar to the message below except the date and time will display the present date and time.
 
Trying 123.456.789.0...
Connected to mail.yourdomain.com.
220-server.host-care.com ESMTP Exim 4.52 #1 Fri, 03 Sep 2005 01:44:37 -0500
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
 
If you do not see the message directly above, your port 25 is blocked and you will not be able to send mail via our servers.
If you are running any firewall or applications that block ports, check to make sure the software/hardware is not configured to block port 25. (Windows XP's default firewall settings do not block port 25).
If you are certain your software/hardware is not blocking port 25, you should contact your ISP to request removal if the block on port 25.
 
If you did connect successfully, confirm the connection by typing helo mail.yourdomain.com then press the return key.
 
If you receive a message response like:
 
250 server.host-care.com Hello mail.yourdomain.com [123.456.789.0],
 
then port 25 is not blocked and you should be able to send mail through our servers (assuming you have configured your email program correctly).
 
If you do not receive any message, then port 25 is blocked and you should contact your ISP to request removal of the port 25 block

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