all. I'm running Windows 2003 Standard with IIS6, MS DNS and SmarterMail Pro 4.3. I want to know how i can setup Reverse DNS on my server so the email send out by SmarterMail won't get rejected.
Creating reverse DNS zones with the Windows Server 2003 DNS service is quite easy, take a look here: http://www.windowsreference.com/dns/how-to-create-dns-reverse-lookup-zone-in-windows-server-2003/.
However, I suspect that you will not be able to solve your problem by configuring your own reverse zone on your internal DNS server. The reason is that DNS PTR records (i.e. reverse DNS) for public IP addresses are usually managed by the ISP to which the relevant IP addresses has been allocated. In other words, when remote servers attempt to lookup the DNS name for your IP, they will query the ISP's DNS servers.
You will have to contact your ISP and ask if they are able to modify the DNS PTR record for your IP address.
Alternately, your ISP may offer an SMTP relay service, i.e. you configure your mail server to relay via an SMTP server provided by the ISP. Most mail servers refer to this as delivery via smart host.
You set up a reverse lookup zone in DNS Manager and create pointer (PTR) records in that zone for your IP addresses. The IP will point to a fqdn of the host that has that IP assigned to it. The reverse lookup zone will need to be accessible to the mail servers doing reverse lookups.