I think you are better off spending your time on this
posting server. It's easy, much easier in my experience
than dealing with newsreaders. (I also use a Mac and have
not tried any Unix-based solutions.)
The first few months, I posted with a newsreader. I had a
checklist: my procedure, what I had to add manually, last
month's message-id for the supersedes, etc. I still got
something wrong every month. And this was when my FAQ had
only one part, not the five it does now.
Once I put it in the server, I've had no further problems.
To put it in the server:
1) add headers to the front of your text file: from,
newsgroups, followup-to, subject, organization, reply-to,
approved, summary. Probably not all required, but I
guarantee this set works. Then a blank line before the
auxiliary headers, which I assume you have already set up.
2) send it to faq-server@rtfm.mit.edu with a subject line of
"add pw 14" where pw is the password you want. The 14 means
to post it biweekly. The server gets everything else from
the body. The password is not terribly secure, so don't
worry about making it strong.
3) if you have multiple parts, send the additional parts to
faq-server@rtfm.mit.edu with the subject "add pw
parent-archive". The pw can be the same as or different
from the parent's. The parent-archive is the name from the
Archive-name secondary header in the first part; this means
to post this part at the same time as the first part.
4) When you need something else, RTFM. The above does not
commit you to anything you can't change, nor does it lead
you to do anything you shouldn't.
Edward Reid