The sample Director configuration (10-director.conf) says that director_servers and director_mail_servers can be lists of either IPs or hostnames:

List of IPs or hostnames to all director servers, including ourself.

Ports can be specified as ip:port. The default port is the same as

what director service's inet_listener is using.

#director_servers =

List of IPs or hostnames to all backend mail servers. Ranges are

allowed

too, like 10.0.0.10-10.0.0.30.

#director_mail_servers =

However, if I use hostnames, it bails out with an "Invalid IP address" error. It also seems to be confusing the dashes in my hostnames for address range specifications.

Obviously hostnames are not currently supported, but I thought I'd mention it so the documentation could be updated.

-Brad