I keep forgetting about mDNS (.local) thing because I disable that in my home network. Reason is that increased the network activity. You can change that to use direct IP address of your NAS. And it should work provided the IP address of your NAS don't change (Either via a reserved DHCP assignment, or setup as a static IP in the NAS config).
Will see if I can finally setup my Pi unit later this weekend so I can test it out in earnest.
Edit: Alright.. Almost certain email system is broken in the Wiki.. Sighz, another thing to fix when I have time.