Why do Internet Service Providers block(ISP) port 25?
Many ISP’s (Internet Service Providers) are blocking what is called “Port 25” which is the port used to send e-mail. For example, the Earthlink, one of the ISP that blocking the port 25. You may get more detail at http://help.earthlink.net/port25/. These ISPs have chosen to do this to cut down on the amount of “SPAM” mail that is sent. All e-mail sent via the Internet is routed through the port 25, the channel used for communication between a mail client and a mail server. Even though port 25 blocking will probably become an industry standard, the filter creates problems for e-mail servers such as KidMail.net because it blocks legitimate e-mail as well as spam. You can check with your dial-up provider to see if they are doing this. Again, the simple solutio is to access KidMail.net SMTP via port 26. If you have a firewall program such as ZoneAlarm or as part of a routing device then please also make sure that port 26 is allowed for your email software. Key concepts in this article: SMT
