Why do I have problems sending email when my Cable / DSL Internet Service Provider has blocked port 25 SMTP?
Recently many of the Cable and DSL Internet Service Providers (ISP) have decided to try to stop the spam email traffic from infected zombie computers from going through their systems. They have chosen to not allow any outbound email through their system that does not have an email address that is with their service. For this reason your domain name email service may stop sending outbound mail and you will begin to get non-delivery messages. You can resolve this issue as follows: Change the advanced settings for your outbound port from port 25 to use port 2525. We have our email services listening on both ports to resolve this issue. Here are the settings for Windows XP using MS Outlook: If you are using a different version of Outlook or Outlook Express, the settings are the same but the window will look a bit different.
