Scoring Spam

Each e-mail is assigned a numerical score, generated by our anti-spam engine. The initial score of a message is "0". We use many techniques to scan each message to see how "spammy" it is. The cumulative value of each test becomes the spam score of the message.

We have two thresholds, defined for each domain, that determine what happens to each message. The more spammy a message is, the higher the score. If the score reaches the tag threshold the e-mail will be tagged. If the score reaches the reject threshold the e-mail will be rejected.

Similarly, we look for evidence that the message is legitimate, reducing the spam score. Thus, the spam score can be a positive or negative number. The higher the number (positive) the more spammy it is; the lower the number (negative) the less spammy.

Tests that result in a high impact are examined first: virus scanning, black/white listing, sender history, etc. These tests take precedence; they can set the message result by themselves and may cause other tests to be skipped.

Some very expensive tests can get very good information about the sender; but they are done last and only if the test can change the disposition of the message.

We examine the traffic patterns between the sender and recipient. For legitimate senders, as their traffic history accumulates, their spam scores drop until the sender becomes implicitly white listed. This ensures their messages will never be blocked in error.

If the message is not accepted or rejected by the high impact tests, it is then classified based on it's spam score and the Tag and Reject thresholds defined for the recipient.

PerfectMail™ uses three categories when scoring messages:

Accept

After being thoroughly scrutinized, the message was deemed wanted and is immediately forwarded to the intended recipient(s).

Reject

Messages that are rejected typically contain any of: unwanted content, obfuscated text, misleading or inaccurate e-mail header and/or envelope information, references to spam-friendly networks or other criteria that strongly indicates spam. As a result, PerfectMail™ refuses the message with an appropriate explanation to the sender. Reject messages are customizable so that in the unlikely chance the message was rejected in error, the sender can contact you by other means (phone).

Tag

PerfectMail™ tags messages that score above the Accept threshold but below the Reject threshold. We "Tag" the subject line of the message [SPAM?] and deliver it to the recipient. The user does not need to check a separate quarantine. Typically less than 1% of all messages are tagged.

Note: Messages containing viruses, unwanted file attachments, or known Phishing (fraudulent) messages are always rejected.