[...]
> i'm trying to replace headers in the ACLs, so i could hint
> SpamAssassin (through exiscan-acl) about the status of callout
> verification.
I do not think that this is a good idea. If you *really* want to use
callout verification, pass the information via a variable to the
router to SpamAssassin.
> however, 'warn message' adds a new header instead of
> replacing the existing one.