There appears to be a lot of spam on this list at the moment. Most of it
appears to be coming from addresses which probably are not subscribed to the
list.
If the list posting policy is 'open' can it be changed to 'subscribed
addresses' only? This won't stop legitimate posts as there is no reason to
post to the ietf list unless you are subscribed to it, but will stop the bulk
of the spammers.
I am suffering the same problem with the Linux Beer Hike mailing list and am
about to make the same change, it was fine for the last couple of years up to
about 2 months ago when the spambots got hold of the address.
Andy