Spamassassin & Email Aliases

[OliverScott]

I had test the setting ...

the user_pref doesn't work on forwarding setting, if I want set the spam for forwarding mail, I had to set the local.cf, but that will effect all the incoming mail.

"user_pref doesn't work on forwarding setting" - what does this mean exactly? I tried changing my user_prefs and they seemed to also be applied to emails forwarded to external addresses OK.

Does this mean that it is the user_prefs of the original domain which are used rather then the user_prefs of the receivers domain, when both domains are on the same DA server?