Public DNS/MX Question
Public DNS/MX Question
So I am thinking of installing Zimbra alongside our existing mail server following the split domain article on here. My confusion lies with public dns setup. Right now we have a public address 200.xx.xx.xx which is tied to mail.example.com. The external address is tied to an internal IP with an MX record. Our users email is setup firstname.lastname@example.org.
For the new Zimbra system should I setup an additional external IP in the same way, 200.xx.xx.xx tied to a separate dns name, mail2.example.com. Using an additional MX record with a lower priority until migration? We want to keep the addresses like email@example.com.
I am confused as to how this will work, specifically when mail is addressed to firstname.lastname@example.org how will it know which system to be delivered to if it exists in both systems? Will it matter if it exists in one system and not the other? Will it try both or one or the other?
Am I thinking about this entirely the wrong way? Maybe we could use the same external IP for both systems and somehow tie both internal MX’s to it and let the priority of the MX determine where the mail is delivered?
Typically in a Split Domain setup you keep one external IP address / host name and one email domain (ie @example.com). You either continue to route incoming email to your existing email server or to your new Zimbra server (this would be your primary server). You then use the Split Domain setup to figure out if the email stays on that server or if it needs to be routed to your secondary server. The Split Domain wiki page has good examples on how to setup the Zimbra server as either a primary or secondary server. The trick is often figuring out how to configure your existing email server to handle the Split Domain.
What software are you currently running on your email server (Exchange, Postfix, etc.)? There is some good information in the forums on some of the more popular configurations. If you can't find anything for your setup post another question with details on your current configuration.
We are running a Mercury mail POP3 setup. One caviat I forgot to mention is the fact that the previous IT regime here setup the Mercury server to also host our company's website. So example.com also hosts our company website on the same server, same IP address as our mail server. :mad:
Part of my thought was with this email migration I could segregate the two, but I was just uncertain on how to cleanly do this.
I don't really know much about the Mercury email server. I remember evaluating the corresponding Pegasus email client, but never really go into looking at the server side. Your challenge will be figuring out how to forward email from the Mercury server to the Zimbra server for those accounts that you migrate. As I mentioned, the wiki page on Split Domains has pretty good examples for handling the Zimbra side of things.
As far as splitting your email server from your web server, in a typical setup you would handle this on your gateway / firewall. Incoming web traffic (presumably port 80) comes into your Internet facing IP address and then you forward it to your internal web server. You do the same thing for email traffic, except you forward to a different internal email server.
You will need to configure postfix as a proxy server, with transport configuration until the migration, for the postfix redirect the message to right mailbox.