Antispam Mail Server | Setting Up Exchange 2000 Server

The practice of flooding Internet forums and personal mailboxes with junk mail is an increasingly common form of advertising, mainly due to its high cost effectiveness and ease of maintenance. Since the mid-90s ad hoc computer programs, commonly referred to as antispam filters, have therefore been developed to fight spam using a variety of techniques.

Common Ways Filtering Programs Identify a Spam Message

The techniques used by antispam software to identify unsolicited e-mails are typically simple. Experience has in fact shown that such messages are often one or a combination of the following:

purposely forged to look like a message sent via Outlook Express;
consisting exclusively of an image, so to prevent the antispam software from checking its text;
missing or with altered headers, typically the 'sender' field, so to complicate the sender identification;
containing misspelled or unusual words.

The reason behind the uncommon or misspelled words is a specific -- but often unsuccessful -- attempt to avoid Bayesian filtering, a complex but extremely powerful technique that has proven to be the most effective to date and is therefore being implemented in all modern antispam software.