Yes, that's correct - I've always used postfix always_bcc and didn't realize
there was one for amavis as well.
If you want to keep it that way, you could declare bcc-user a spam_lover:
@spam_lovers_maps = ([
'bcc-u...@gambit.example.com',
]);
It would also be very helpful to have a better description of the syntax I
needed to use here for wildcards.
What's the difference between the new_RE() form and the hash-type lookup table? How do regular expressions work for the hash table
to match an entire domain, for example?
The hash-type lookup is not a regex lookup. See [1].
[1]
https://gitlab.com/amavis/amavis/-/blob/v2.13.1/README_FILES/README.lookups#L114-124