We are going to migrate our SBS2003 server from downloading e-mail via the POP3 connector to getting e-mail sent directly to the server via SMTP. The static IP address is already setup and working. Following is the procedure I've come up with. Did I miss anything, or have anything unnecessary?
• Preliminary Setup (several days before we start all of this) ○ Change TTL on MX DNS record to something short (like 15 or 30 minutes). ○ Forward port 25 to the server (Cisco router configuration). ○ Make sure everything still works. • Switch outgoing mail to not go through Godaddy anymore. ○ Run E-mail and Internet Connection Wizard on server. § Change it to "Use DNS to route e-mail". ○ Make sure outgoing SMTP works. § Make sure we aren't running an open relay (spammers could send e-mail via our e-mail server): DNSGoodies • Switch incoming mail to not go through Godaddy anymore. ○ Run E-mail and Internet Connection Wizard on server. § Check the box "Use Exchange" (both boxes will be checked, so we are getting e-mail both directly via our server and via Godaddy. ○ If we can test receiving e-mail without switching the MX DNS record to the new address, do it now. § Could possibly be done by setting up a subdomain's MX record to point to our server. § Could possibly be done by sending e-mail to test@IPAddressHere. □ Could not get this to work with a different Exchange server already setup for SMTP. ○ Switch the MX DNS record to point to MyIPAddress. ○ E-mail should switch over within 30 minutes, may take up to 48 hours (depends on TTL of MX record). ○ Test receiving e-mail on at least one account. § POP3 Connector should be disabled for that account to eliminate chance of the mail going through Godaddy while we think it's coming straight to our server. § Don't need to disable it for all accounts ○ Make sure our server doesn't cause backscatter • Post Setup (several days after everything is working) ○ Change MX DNS record to something longer than 15 or 30 minutes. ○ Run E-mail and Internet Connection Wizard on server. § Uncheck the box to use the POP3 Connector. ○ Make sure that e-mail is still working. ○ Keep a watch on Spamhaus to make sure we don't end up on a list of known spammers. ○ Setup anti-spam filter based on this. § Instructions