Problem with mail delivery

[Thomas J. Rude]

To All-

I am having trouble with getting our mail delivered in/out of the
company.  Just so you know, I have zero experience with DNS and have
inherited this project.  I've done some research on the Internet as well
as reading DNS and BIND.  Unfortunately, I still cannot get mail
delivered to our e-mail server nor sent outside of the company through
the Internet.  I have provided the necessary (I think/hope!) info below.
 Any help/guidance/info will be greatly appreciated as I have been
frustrated beyond belief!  Even after we hired a DNS consultant to come
in and configure, it does not work.  Internet access from the
DNS/Firewall server works, as does Internet access for all clients
behind the firewall (http, ftp, telnet, traceroute, etc.).  It seems the
only service lacking is mail.  We are running NT 4.0 SP4 and use MS
Exchange Version 4 SP3.  Also, the old configuration is in place as it
works fine.  The new configuration is on a new server and only in place
when I am testing it (with the obvious hopes of rolling it out once the
mail works correctly!).  Also, we use Meta Info DNS 2.1 on old and 4.1
on new.

OLD Config works fine:
man-gill.com.db
; Subnet 207.206.8
; Subnet 127.0.0
; Subnet 172.16.2
@   IN   SOA   mgntfw.man-gill.com.   tjrude.predict-dli.com (
		1997032062       ; serial
		10800      ; refresh
		3600        ; retry
		604800     ; expire
		86400 )    ; minimum
;
; Nameserver (s) for the man-gill.com domain.
;
man-gill.com.     IN     NS     ns1.man-gill.com.
man-gill.com.     IN     NS     ns2.iagnet.net.

;
; Mail server(s) in the man-gill.com domain.
;
man-gill.com.     IN     MX     10     mx1.man-gill.com.

;
; Address record(s) for the man-gill.com domain.
;
localhost     IN     A     127.0.0.1
@               IN     A      207.206.8.34
mgntfw       IN      A      207.206.8.34
mgntfw       IN      A      172.16.2.111
mx1           IN      A       207.206.8.36
xl_dli          IN      A      207.206.8.39
xl_pt          IN      A       207.206.8.38

;
; CNAME alias record(s) for the man-gill.com domain.
;
ftp             IN      CNAME       mx1.man-gill.com.
ns1           IN       CNAME      mgntfw.man-gill.com.

;
; Records that were not automatically handled by MetaInfo DNS
Configuration
;
mx1.predict-dli.com      IN     A   207.206.8.55
valiant.predict-dli.com   IN     A   172.16.3.201
man-gill.com                IN     A   207.206.8.34


NEW Config mail doesn't work:
predict-dli.com.db
;
@ IN SOA ns1.predict-dli.com   dns-admin.ns1.predict-dli.com.  9  10800
1800  604800  86400
ftp                                 IN    CNAME   mx1
ns1                               IN    CNAME   mgntfw
mx1                              IN    MX          10
mx1.predict-dli.com.
mgntfw                          IN    A             172.16.2.111
valiant                           IN    A             172.16.3.201
xl-dli                             IN    A              207.206.8.39
xl-pt                              IN    A             207.206.8.38
  ; valiant re defined
valiant                           IN     A             207.206.8.55
localhost                       IN    A              127.0.0.1
ns1                               IN    A              172.16.2.111
@                                 IN    NS
ns1.predict-dli.com.


Other info you may find useful:
mgntfw = netbui name of checkpoint firewall
valiant  = netbui name of e-mail server and visible web server
(valiant.predict-dli.com)
external ip addresses:
	207.206.8.34 = firewall/dns
	207.206.8.55 = valiant
	207.206.8.38 = internet traffic from users at xl-pt as translated by
firewall
	207.206.8.39 = internet traffic from users at xl-dli as translated by
firewall
internal ip addresses:
	172.16.2.111 = firewall/dns
	172.16.3.201 = valiant
	172.16.3.0 = xl-pt internal network
	172.16.4.0 = xl-dli internal network
Yes, we used to be man-gill chemical and hence the man-gill domain.
However, we are now predict-dli and hence the predict-dli domain.  VERIO
NW hosts a major company web site out in seattle (www.predict-dli.com).
I changed the configuration from old to new because I wanted to reflect
our changes as a company.  Do I need to notify VERIO NW since I do have
they are listed as our secondary DNS servers (network solutions)?  Also,
from what I understand, any e-mail addressed to one of our employees is
sent first to VERIO NW at which point their servers forward it to
207.206.8.55 (our valiant machine) and Valiant moves it to the
respective employee.
I apologize for the length of this post, but I hope it gives you the
needed info to offer some help if possible.  I would really appreciate
it!

Sincerely,
Thomas