So I managed to get spam filtering working: gnus is now recognizing
emails from senders on my blacklist, flagging them as spam, and sending
them to the spam folder. However, I also have whitelist filtering turned
on, both here (in my init file):

,----
|    ;;Spam-filtering
|       ;;See: http://spamlinks.net/filter-bl.htm
|     (setq spam-use-blacklist t)
|     (setq spam-use-whitelist t)
|     (require 'spam)
|     (spam-initialize)
|     (setq nnmail-split-fancy '(| (: spam-split)  "mail.misc"))
`----

... and in the customization buffer for my mail.misc folder:

,----
| + Tick:
|   + [X] Spam Summary Exist Processor
|   + [X] Spam: Blacklist
|   + [X] Ham: Whitelist
| + Tick:
|   + [X] Spam autodetection: on (non-nil)
| + Tick:
|   + [X] Spam autodetection-specific methods (use specific methods)
|     + [X] spam-use-blacklist
|     + [X] spam-use-whitelist
| + Tick and supply value:
|   + [X] Destination for spam-processed articles at summary exit:
|         Move to a group: _spam_
|   + [X] Destination for ham articles at summary exit from a spam group:
|         Move to a group: _reclassify_
| + Tick:
|   + [X] Ham mark choices:
|     + [X] gnus-ticked-mark
|   + [X] Spam mark choces:
|     + [X] gnus-spam-mark
`----

... so everything _looks_ like it should work, but if I have an entry in
my blacklist specifying that an entire domain should be considered
"spam", e.g:

,----
| @yahoo.com
`----

... and then add exceptions to my whitelist:

,----
| purgat...@yahoo.com
`----

... mail sent from the whitelisted address is still flagged as spam
regardless. What am I missing here?

--
Michael Audas
gopher://sdf.org/1/users/mrgnash
Sent from Gnus/Emacs.