Because I am too stupid to pull this out of my shell history or make an alias for it, I post the one-liner I use to extract From addresses from email that my spam blocker incorrectly flags as spam. Those addresses end up in my white list.
grep ^From: fix | perl -pe 's/From:\s+//; s/.*<(.*@.*)>.*/$1/' | sort | uniq >> ~/.procmail/goodfile
I suppose that is rather unixy, those other programs have Perl implementations somewhere.
Now I'll probably forget how to find this post, too.