Gnus is quite fast
when scoring the “traditional”
headers—‘From’, ‘Subject’ and so on. However, scoring
other headers requires writing a head scoring rule,
which means that Gnus has to request every single article from
the back end to find matches. This takes a long time in big
groups.
You can
inhibit this slow scoring on headers or body by setting the
variable gnus-inhibit-slow-scoring. If
gnus-inhibit-slow-scoring is regexp, slow scoring is
inhibited if the group matches the regexp. If it is t, slow
scoring on it is inhibited for all groups.
Now, there's not much you can do about the slowness for news
groups, but for mail groups, you have greater control. In
To From
Newsgroups, it's explained in greater detail what this
mechanism does, but here's a cookbook example for
nnml on how to allow scoring on the
‘To’ and
‘Cc’
headers.
Put the following in your ~/.gnus.el file.
(setq gnus-extra-headers '(To Cc Newsgroups Keywords)
nnmail-extra-headers gnus-extra-headers)
Restart Gnus and rebuild your nnml overview files
with the M-x nnml-generate-nov-databases command. This
will take a long time if you have much mail.
Now you can score on ‘To’ and ‘Cc’ as “extra headers” like so: I e s p To RET <your name> RET.
See? Simple.