spam blocker temporarily went amok

[Christopher Faylor <cgf@redhat.com>]

I temporarily broke the spam blocker.  It's amazing how much spam got in
in the brief (~3-5 minutes) time that it was broken.

During that time you might have seen increased spam and one or two duplicated
posts.

Sorry about that.  I had added some new code as a preparation for doing
the mailing list address munging that I talked about.  Before switching
over, I verified that mail still got through to the mailing list but
forgot to verify that mail *didn't* get through.

The code that I added allows the mlcheckd process to filter email and
add headers.  I have added an "X-IsSubscribed: yes" to the headers of
email in the cygwin mailing list if the mail came from a subscribed
address.  It isn't foolproof but it might be helpful in knowing when to
cc someone.

I also added a "cygwin-replyto-subscribe" address.  If you subscribe to
cygwin-replyto, then mlcheckd will automatically add a reply-to:
cygwin-BLAH-cygwin-SPLAT-com to any messages that come from you.  This
should cut down on the constant stream of "There is no need to send me
personal email" that shows up on the cygwin list.

Future enhancements will be an opt-in method for removing the long
company disclaimers and possibly a way to automatically munge the From
address.

In unrelated news, I just added SORBS to the rbl checking.  So far it
has managed to block one valid message.  I have been noticing a good hit
rate with SORBS for my own spam, so I'm hopeful that this might have an
effect on sourceware.org.

Anyway, apologies for the increased spam.

cgf