Why do Internet Service Providers block port 25?
Hundreds of thousands of computers worldwide are infected with virus or trojan horse programs which, completely invisible to the user, put their computers under the control of spammers who use infected computers and their Internet connections without their owners’ knowledge or consent to send out tens of thousands of unsolicited commercial emails per day. Because of anti-spam blacklists which reject mail coming from computer networks regularly abused by spammers, it is a liability for ISPs not to block outgoing mail. If an Internet Service Provider is placed onto one of these blacklists, they may find that their customers are suddenly unable to send email to thousands of servers across the world. These Internet Service Providers typically provide their own mail servers to be used for sending mail, and you should use these in the event that your ISP blocks access to Interkey.net’s outgoing mail servers.
