XigmaNAS

As not everybody has a static domain name from ISP, it should not be mandatory to enter a domain name after hostname.
I stumbled on bug #175 "ProFTPd: Changes could not be applied (Error code 1)" when not using domain name, and prefer empty domain name instead of 'local', until I can afford a business ISP.
Before making system.php allowing empty domain and creating /etc/hosts with static or dynamic IP address and hostname, to fix ProFTPd startup failure, create /etc/hosts right before starting it. Insert the following line into /etc/rc.d/proftpd at the beginning of the mkconf function:
echo `ifconfig vge0 inet | tail -1 | awk '{ print $2 }'` `hostname` >>/etc/hosts
(replace vge0 with your network interface name, or better fetch it from configuration)

Not using .local is your choice, but it is the official standard for networks without a domain name. http://en.wikipedia.org/wiki/.local However, you can use a your dynamic dns domain (no-ip.com) or just make something up. But networking assumes a fully qualified domain name.