long header fields

[Bill Heiser <bill @ bh . org>]

I have a large population of e-mail users who insist
on using very long CC and TO lines majordomo-run
lists in their messages.  As a result I frequently get
majordomo bounces complaining about "header field too long".

Before I change "MAX_TOTAL_HEADER_LENGTH" in majordomo.cf,
is there a stated "official" maximum limit to this?  I
see the default is 1024.  I didn't see anything specific
mentioned in RFC822.  The MTA is sendmail 8.8.x.

Any thoughts on this?

Thanks in advance.
-Bill