[SOLVED] External DNS for multiple email domains

[Nox]

Ok, simple question (hopefully)

If I want to host multiple email domains on one mail server, can I use the MX record for one domain to point to a host on another domain?

Example:


in maildomain1.com the MX record = server.maildomain1.com
the A record for the server = IP

in maildomain2.com the MX record = server.maildomain1.com


in the maildomain2.com there are no host records, because technically there are not any servers. The server that it is hosted on is in maildomain1.com.

Is this valid? If it is confusing, I appologize. I can post zone configs if needed.

[phoenix]

You'll want an A & MX record for each domain that you have on your Zimbra server, other than that you can point as many domains as you like to the server. I do that with several domains and no problems.

[uxbod]

Phoenix,

surely you would only require a 'A' record for the primary domain which hosts the mail server itself. For the other domains a MX record would suffice. The caveat to this though is that everybody, who is not in the primary domain, would need to authenticate with the full email address and not just the user element.

I appreciate that your advice is indeed correct, but added this for additional clarification on configuration.

Am I correct in my statement ?

[dspillett]

As an addition to uxbod's details: I have several domains pointing to one server, some with just the MX entry and one or two with an A record too, and it works fine.

Having the A record point there has the advantage of users being able to login using just the name part of their address (rather than name@domain). It also helps you if you have reason to try to keep services visibly separate (so company2 doesn't go to http://zimbra.company1.com to get their mail and calendar, for instance).

On disadvantage of using the A records is present if you use HTTPS with a not-self-signed certificate - only one domain can have the valid certificate [unless Zimbra can be easily convinced to operate on multiple IP addresses and associate each address with a specific domain with it's own certificate].

In short: just the MX record will work fine. Adding the A record goes a little way to keeping up appeareces but isn't important other than that.

[Nox]

I am glad to see that I can do that. The added 'A' records just seemed redundant to me. In this case other than the primary domain, one of the additional domains is used for public mail communication testing (so as not to affect the production email server), and the other email domain has exactly 2 people (sales division). So they will all be connecting to the same HTTPS server webmail.company.com.

Thanks again!