DNS Configuration Expert Help Needed!

I have a group of MS Windows 2K3 servers on static IPs behind a Sonic Wall hardware firewall using NAT. I cannot get the DNS configuration to pass inbound e-mail to a dedicated e-mail server. I can send outbound e-mail. Immediate PayPal payment and positive feedback given upon successful completion of task. Confidentiality and non-disclosure required. Future freelance IT work guaranteed. Please put SCOT in your bid. Automated responses will not be considered.