System naming

[Mistoffeles]

How do I go about naming my server before installing Zimbra so that I will have users on the "main" domain whose email addresses are x@example.com, not x@mail.example.com?

I would prefer to have the servers have names like mail and web or www, on the same domain, so their FQDNs would be mail.example.com and web.example.com (or www.example.com), but incoming mail addressed to x@example.com must be accepted and directed to the correct user, and outgoing mail must come from x@example.com, not x@mail.example.com.

TIA,

-Misty

[phoenix]

The first time you run the Zimbra installation you are aksed if you want to set the domain name, the default is to use the FQDN of the server, if you answered yes then you could have done it in there. The only method to go through that procedure is to uninstall Zimbra the reinstall to get to the prompt.

If you wish to rename a working server then back it up and the run zmsetservername, it should be straightforward but make sure you read and understand the document before running it.

You should also make sure you understand the implications of having a correct DNS set-up, as mentioned in the article.

[Mistoffeles]

Ok, this isn't really what I asked, or at least not what I meant to. I will try to be more clear.

I have an old server that needs to be replaced. It is currently named in the format example.com, and it handles email and websites. I want to replace it with two separate servers, one for email and one for websites. My original intent was to name them in the format mail.example.com and Example Web Page, where the www one would also answer to example.com.

In my first attempt at building an email server, I named it like mail.example.com, but when Zimbra was installed, all the email was being sent out as x@mail.example.com instead of x@example.com, which is not acceptable.

How do I go about setting this email server up so that email which is addressed to x@example.com is received (and prefferably also x@mail.example.com but not necessarily), and mail sent from this server is addressed (and reply-to set) only as x@example.com? Keeping in mind that I will need to provide webmail (through webmail.example.com, or zimbra.example.com, or whatever), and I will need to be able to create other email domains such as freddykruger.com (with webmail.freddykruger.com) and jasonvoorhees.com (with webmail.jasonvoorhees.com) on the same server.

(obviously the domain names aren't ones I will be really using)

Can I have both the email and web servers named example.com internally? I'm not sure I want to even do this, as I have several servers that are all part of the same domain (i.e.: xanadu.paradise.com, elysium.paradise.com, ecstacy.paradise.com, bliss.paradise.com).

Am I better off just using the prefix names, like xanadu, elysium, ecstacy and bliss, but telling Zimbra that it is "paradise.com"?

This whole DNS thing is a really messy issue for me, I am not at all fond of it.

[phoenix]

I've already given you the answer in my first paragraph but just in case I've confused you and for clarity.....

You give your server an FQDN of, let's say' mail.yourdomain.com and during installation you get to the step where it asks you if you want to change the domain name, answer yes and enter the domain as yourdomain.com (note, that's the domain name not the FQDN of your server).

Mail will be sent from the server as this: user@yourdomain.com, further domains can be added to the Zimbra server if you need/want as yourdomain2.com, yourdomain3.com etc.......

You will at this stage already have set-up your DNS A & MX records for yourdomain.com to point to your LAN IP (the A record) and the MX record has a name of mail.yourdomain.com - you will have verified this before you do the install by running the following commands:

cat /etc/hosts
cat /etc/resolv.conf
dig yourdomain.com mx
dig yourdomain.com any
host `hostname` <-- type that exact command with backticks not single quotes and do NOT put your hostname in there

If you don't understand what the output shows you then search the forums for further explanations or post it here. Setting up a Split DNS is remarkably simple and is nothing to fret about.

If you have a webserver in your domain then you would have an A record that points to the IP of your web server, like this:

yourdomain.com. IN A 192.168.x.x  <-- your web server LAN IP

and anyone on your LAN that types yourdomain.com gets to the web server and anyone that types mail.yourdomain.com gets to the mail server. Does that answer your question?

[Mistoffeles]

So Zimbra requires the DNS in place and working before it is set up?

I am building these systems on a different network than where they will be deployed, so I have no way to assign them the IP address they will actually be on in the end.

That brings up another matter, which is whether it is better to NAT the Zimbra machine and configure it to recognize that it is acting as the external address in the DNS despite being configured as the NATted address, or just do a pass-through on the router (still with the firewall rules blocking all ports except as needed to run Zimbra and remotely administer the server) and configure the machine with the IP address in the DNS. There are no clients in this NATted network, only servers, and they do not need to talk to one another.

- Misty

[phoenix]

You need to give Zimbra the LAN IP address so it can resolve it's name via DNS (it's required by postfix) and forward the necessary ports, you do not give it your external IP.

[Mistoffeles]

ok I'm missing something here...or someone is.

Are we talking about the local BIND9 service or internet DNS? Why would I care if the internal IP address can resolve to the mail server? I want people out on the internet to be able to send email on this server, not people on the local network (as there aren't any user workstations on the local network, this is a colocation site and has nothing but servers on the LAN).

All email users of this system will connect via the external IP address, not the address set in /etc/sysconfig/network-scripts/ifcfg-eth0. The only time there is a user on the LAN is when I am on-site with my laptop plugged into the router to work on the machine, which I really would rather never have to occur though sometimes I have no other choice.

I suppose I should also ask whether I should put the internal or the external IP address in /etc/hosts, since the only email users will be accessing it using the external IP address as returned from the internet DNS.

To put it more clearly, the server's IP address is 192.168.5.115 (LAN), this is 1:1 NATted on the router to 201.201.72.15 (internet) (examples, not the real numbers). To all users, the server's IP address is 201.201.72.15, there is not a single email user who will use 192.168.5.115.

This DNS stuff really makes me dizzy sometimes.

[uxbod]

If you are NATing the address then you will need to setup a Wiki :: Split DNS architecture so that the A and MX record point to the internal LAN IP address of your ZCS server. Obviously the public DNS entries will still point to your external IP.

[Mistoffeles]

I don't understand why you think I need to do this, there is nobody on the inside of the LAN who needs to access email.