I think that can be already specified by --server-file. Each domain
would be listed as --server=/blocked.example.net/, which implements just
--local= option. Of course that requires some decoration around just
list of domains. It is not possible to load just domain per line file
into dnsmasq.
I know in the addn-host you can specify additional hosts files. It would be
great to extend the syntax, so we can block some domains (ipv4 and ipv6).
Currently I add some domains with 127.0.0.1 or 0.0.0.0 to blacklist them but it
seams not to be really the same than be resolved to NXDOMAIN, since