X-ListMember (and other) headers

[darrell <darrell @ halo5 . net>]

I've been searching and searching but I can't find out how (or if it is
even possible) to add headers to outgoing messages with Majordomo.
Specifically, I'm trying to add X-ListMember, but I may end up adding more
later, if I can. Here's what I'm using:

Majordomo 1.94.4
Perl 5.005_03
Sendmail 8.9.3
RedHat 6.0

Thanks in advance for any help.

Darrell Swoap