The mechanism by which spam probabilities are calculated, and the actions associated with probability thresholds, are described in the Tuning Spam Detection section.
- Tag and Deliver: Alter the "Subject" header of messages delivered to end users, generally if the message's spam probability is over a certain "threshold". For example, the default policy alters the Subject header if the message's spam probability is greater than 50%. Users can implement filters within their email client based on the subject line modification, as described in the End User Management section of the Administrator's Reference.
- Silently Tag and Deliver: Add a custom message header that records the spam probability and the anti-spam rules that were triggered by the message. The default policy adds an X-PerlMx-Spam header to all messages with a spam probability. Custom headers are not visible in most client email programs.
- Quarantine: Quarantine messages with a spam probability greater than a specified percentage, allowing administrators to review quarantined messages. It can be used in conjunction with the options described above. By default, the PureMessage policy copies messages with a probability of 50% or greater to the quarantine.
- Quarantine and Digest: Move messages above a certain probability to the quarantine. Quarantine Digests inform users of which messages have been quarantined.
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