The SMTP server is refusing my connection attemptsThe standard port used for SMTP connection is 25. Most often the reason for refused SMTP connection is that your Internet service provider blocks this port. That's why we recommend to you use the alternative port 2525 for your email SMTP connection.
How to run port 25 check?
1. Check port 25 with a Windows OS
Please click on the Start menu button, usually located on the left low corner of the screen. There is a tab called "Run". You have to click on it, in order to proceed further. You will notice the appearance of a new small window on the screen. In the text field of this window you need to type "cmd" and then press the "Enter" key. Another window will open. It is the so called "MS-DOS prompt" or "command prompt". Just type the following command in the command prompt window:
telnet my-domain-name.com 25
2. Check port 25 with Apple/Mac
Each Mac OS is delivered with a preinstalled terminal emulator. The terminal is a tool which allows you to execute commands from the command line. Usually, the terminal is located under your Mac HD -> "Applications" directory -> Utilities sub-directory. When the window opens, you will see a command line with a flashing cursor on it so you can start typing right away. Just type the following command:
telnet my-domain-name.com 25
3. Check port 25 with Linux
Please open your favorite terminal emulator and execute the following command in order to telnet your website:
telnet my-domain-name.com 25
Results from the 25 port check
If the test is successful, you should receive a message like this:
220-serv01.siteground173.com ESMTP Exim 4.63 #1 Wed, 18 Apr 2007 07:17:30 -0500
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
If you get a message saying that the connection is refused we recommend that you use he alternative port 2525 for your SMTP connection.
How to change your SMTP port to 2525?
For instructions how to change your SMTP port at Outlook:
http://support.microsoft.com/kb/262658
For instructions how to change your SMTP port at Outlook Express:
http://www.microsoft.com/windows/ie/community/columns/mailserver.mspx
For instructions how to change your SMTP port at Thunderbird:
http://kb.mozillazine.org/Thunderbird_:_FAQs_:_Multiple_SMTP_Servers