Hi there,
First of all, thank you very much for your reply! I'm sorry I wasn't able to respond; things have been hectic and thus far I haven't needed to implement this, and now that I try, I seem to be having some problems.
Currently I'm using a dummy domain I bought cheaply to test these things with, and the DNS Zone - through WHM on the VPS - looks like this:
myserver.co.uk. IN NS
myserver.co.uk. IN NS
myserver.co.uk. IN A 1.2.3.4
localhost IN A 127.0.0.1
myserver.co.uk. IN MX 0 myserver.co.uk.
mail IN CNAME myserver.co.uk.
www IN CNAME myserver.co.uk.
There are then other entries for ftp, whm, etc, which all specify the same IP as myserver.co.uk (listed here as 1.2.3.4).
I have tried to follow your suggestion, and make sure that WWW is still on the VPN but the non-WWW is shifted to the VPN.
Now, I understand how this works (at least, I think I do!) - but nothing seems to work 100%:
* If I change the myserver.co.uk A record, then the mail stops working - I can get the www to continue working by specifying the IP address as an A record, but the mail will either stop receiving, stop sending, or both.
* Changing the mail entry to an IP permits sending, but not receiving as the MX entry points to myserver.co.uk. which is now pointing at the VPN.
* I cannot change the MX entry to localhost, or to an IP address, as it generates an error.
* I cannot use @ as an A record to redirect all traffic that doesn't specify a prefix, as WHM changes it back to "myserver.co.uk.".
I've tried every combination of these and nothing seems to work, unfortunately. By changing the DNS Zone I can definitely keep WWW traffic on the server and push everything else through to the VPN server, but I cannot keep the E-Mail server running on the VPS server using this method - I can't change the MX entry to suit my needs.
Would it be easier to simply point the domain to our Server 2008 machine, and set up the DNS Zone on that to redirect all WWW and E-Mail traffic back over to the VPS? And would there be much of a penalty in efficiency, given that it's an extra "hop" on the route? Our site is fairly basic and uses nothing high-bandwidth anyway, but I want to be as efficient as possible!
Any advice would be GREATLY appreciated - thank you!
-AndyH