HELP: Zmailer/MX and SMTP issue.

["Aaron D. Kulick" <kulick@navin.com>]

Dear Sirs,

I will admit first off that this problem most likely (or in fact most
definitely) does not pertain to a fault with zmailer but a configuration
error of my own.  Please though, any help would be sincerely appreciated
or even a redirect to a FAQ, forum, or book.  I apologize for my
ignorance, the O'reily DNS book for both DNS and Sendmail (hoping for a
clue) have yielded nothing immediately obvious.

Particularly, I have zmailer running as MX priority 10 and the another
mailer running at MX priority 1 for my domain.  Now my problem.

Internally, mail delivery is fine as is inbound mail (tested, I used the
CGI tool already on the zmailer.org page, kudos to the author), however,
when a host (from within my domain) specifies the zmailer server (MX 10)
for SMTP traffic to hosts/destinations outside of my domain I receive
the "target address is not our service MX client" message (which
invariable suggests that this is a DNS issue with an obvious answer
"change the MX priority of the Zmailer server" (however, a complete swap
is immediately impossible and I was hoping to perform a slow migration
since there are hundreds of accounts that cannot tolerate interruptions
of ANY kind).  What must I do (if it can be done) in order for the
zmailer host to A) accept the SMTP traffic and B) send it merrily on its
way without (and I must stress that this is whole point of this
convulted exercise) using the primarily mailer which I so desparately
would love to chuck out a window and replace with zmailer, my ultimate
goal?

** Begin Self Deprication **
Again, quite honestly, I throw myself at your mercy and quite
shamelessly hope to arouse your pity.  I apologize immediately for the
potential "off topic nature of this question".  Again, though the
solution here may be obvious to you, as I have demonstrated above, my
ignorance is obviously expansive allowing me to embarrass myself before
countless individuals whom I hope will help me.
** End Self Deprication **

Sincerely,

Aaron D. Kulick
Navin.com, Inc.