What is AWL?
The auto-whitelist. (note: this is NOT related to whitelist_from, etc.. those are the manual whitelist tools, this is the automatic one. )
how can I change it?
You can turn it off, as per Theo's suggestion.
(IMO, it should be off by default to maintain consistency with past versions, but it's not)
If it's lying anyway, can I get away with rescoring this rule? (header AWL -7.8)
No, it doesn't have any fixed score, it's an averaging system.
Read the fine wiki on this subject, it can tell you what the AWL is, how it works, and what things to expect of it.
http://wiki.apache.org/spamassassin/AutoWhitelist
