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Not with the auto-whitelist! The auto-whitelist is an averaging system. Instead, you want to use the manual whitelist. See ManualWhitelist.
CAUTION: AutoWhitelists Work Differently for Most Other Products
Most other products use an AutoWhitelist as automation of a manual whitelist, which is created and/or maintained by monitoring outgoing email to add entries to a whitelist without a need for human intervention.
In essence, rather than adjusting a sender's average score, as in SpamAssassin, most other products literally automate the addition of names to the manual whitelist.
Because autowhitelist-ing is an industry standard term for automation of a whitelist, this feature in SpamAssassin should be re-named to better align with what it actual does, such as maybe AutoReScore?
In essence, be aware the term AutoWhitelist means something else on most (if not all) other anti-spam products.