How can i host my mail server?

Question

Can someone tell me step-by-step how to host a mail server?internet resrouces on this subject are useless. I have a leased line with 12 IPs and an exchange server(2003) which pulls mails from the ISP's mailbox that we have reserved. We have a domain name reserved too.Please tell me what has to be done for me to be able to access mails by jus typing mail.companyname.com. I have configured a cisco router for NAting the private IP assigned for the server to one of the reserved public IPs.

Answer 1

1) register your domain

2)Create an MX record for your domain.  It need to point to the ip affress used by your exchange server

3) configure your exchange server