Well I’m going to answer my own questions and maybe help someone else out.
I created a Linode server dedicated to MIAB. I got a domain especially for this, did the glue records and it all works just fine. I then decided to add a new user (meaning another domain on which I already had a website.) I didn’t want to have MIAB be the DNS nameserver but it ends up being easier that way so I changed the registry record to the ns1.box.new-domain.com names like the guide says.
What is not in the guide are the other important steps that I found necessary.
In the Custom DNS screen of the Admin site I found it necessary to add these three records:
Domain Name Record Type Value
new-domain.com A xx.xx.xx.xx (IP of web host)
www.new-domain.com A xx.xx.xx.xx (IP of web host)
webmail.new-domain.com A yy.yy.yy.yy (IP of Linode server)
First two URLs will resolve to the website and the last one is:
and resolves to the RoundCube login.
I don’t know why the guide does not give these instructions… or maybe I screwed something up and required them. I don’t know, but everything works. (One item… I don’t think the MIAB DNS propagates all that quickly so give it several hours before you expect it to work.)
Here is another item that might bite you. If you sent mail out of the web host’s SMTP to your new domain to test and you have a site running for that domain many ISPs will take a shortcut and ignore DNS and try to pop the email in the local server. When it finds none it sends it back to you with an error 553 “We don’t accept mail for this address.” To fix this either tell the IP to disable this for you or often putting in a custom DNS MX record on the web host (same one you used on the MIAB) will work. Yes, I know that the web host is not being used as a nameserver but often the internal host SMTP will see that there is a MX record on file for the domain and will follow it.
I really don’t want MIAB being the DNS provider. I’d rather have my registry do it so I’m going to try to figure out how to use the registry as the DNS provider for the new domain. My guess (and it is only a guess) is I’ll need the 3 A records above plus a MX record pointing to the box.server-domain.com. I’ll report back here if I ever figure it out.
======= UPDATE ==========
It was quite easy to use an external DNS for the user domain that has a website on it. Most registries offer DNS service and if yours does here is how you do it.
Set the nameservers to your registry default
Go into the area where you can create custom DNS records and create the same A records as above.
Add an MX record pointing to the IP of your Linode server host name: 10 box.xxxxx.yyy .
Wait a bit for propagation and you should be good to go.