> If all the rule does is check for uri's in a certain form, then I would
say
> that this specific rule can backfire on completely legitimate mail.
Essentially ALL spam rules "can" misfire on legit mail. In fact
statistically most of them WILL misfire on some small percentage of legit
mail. If they are tested and scored reasonably then there should be a
fairly small chance of legit mail getting tagged as spam. If they are
scored appropriately no one rule will make a mail spam, it will take at
least two hits on the mail from different rules.
Of course mail patterns change with time, and the corpus used for scoring
isn't world-wide. So there are certianly the occasional need to rescore a
rule that is found to hit more ham than expected.
Loren
