Freeloading commercial emailers do more than fill your mailbox with unsolicited email. They also steal server time and network bandwidth, and have even crashed mailservers. And if your mail server can be used as a relay for spam, you may find your site "blackholed", cut off from sending email to many sites, in addition to getting thousands of angry email messages from the victims of the spam. . . .
Freeloading commercial emailers do more than fill your mailbox with unsolicited email. They also steal server time and network bandwidth, and have even crashed mailservers. And if your mail server can be used as a relay for spam, you may find your site "blackholed", cut off from sending email to many sites, in addition to getting thousands of angry email messages from the victims of the spam.

It used to be easy to track down spammers. And all it took to block spam were firewall or mail server rules that denied access from the spammers' domain. Spammers today use commercial tools designed to hide the source of the spam, as well as use third party sites as relays so the spam won't be blocked before it reaches its victims.

SMTP (Simple Mail Transport Protocol) not only makes spam possible, but it also makes it possible to track back spam to its source. All it takes is the ability to read and understand mail headers, and knowing something about how SMTP works. By denying spammers access to relay sites, we can stamp out unsolicited commercial email (UCE).

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