THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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The first stanza filters all incoming mail through SpamAssassin and tags probable spam with a unique header. This rule will use a lock file `spamassassin(spamassassin.lock', ); this is a good idea to do if there will be more then than one instances instance of SpamAssassin working on a message. The next stanza protects against errors. If spamassassin returns an error, it is passed back to the mail transfer agent and ; this improves robustness of mail delivery.
Most people prefer to have spam blocked and saved to a file in your their mail directory. The next stanza instructs procmail to save any tagged messages to a "caughtspam" folder in your procmail MAILDIR directory.
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Read 'man procmailrc' and 'man procmailex' for futher details and explanation. Wiki Markup