I have been asked some questions about the mailing list header line Precedence: ... after having mail blocked by ISPs for use of the extension Precedence: junk and Precedence: bulk, both of which I understand are very appropriate for mailing lists.
Now I can find brief reference to their use in the new Sendmail book BUT I am unable to find any RFC for their use from first principles or other places where I can read about these header lines in depth. Anyone got any pointers? Thanks. Regards, Andrew
