This is ridiculous. The IETF is not getting a lot of spam, so adding SpamAssassin headers is a solution in need of a problem.
I think this kind of filtering violates the IETF charter on public participation. SpamAssassin in particular uses many dubious and revenge-oriented blacklists to make it determination, and labels much non-spam mail as spam. Using SpamAssassin this way just enables these revenge blacklists to suppress IETF mail, which is inappropriate and a violation of IETF rules on public participation. Furthermore, such revenge blacklisting is a group boycott in violation of anti-trust law (see Exactis V. MAPS for a good example). Many businesses participate in the IETF, and would be harmed by a group boycott. It would be unlawful for the IETF to participate in an illegal group boycott which harms legitimate business. If individuals want to scan their IETF mail with SpamAssassin, then they are free to choose to do that themselves. Dean Anderson CEO Av8 Internet, Inc
