Generate zone files for domains with only mailhost in them

src/hostinfo/named.py

@@ -232,6 +232,12 @@ def generate_forward(tree, hosts):
     for c in tree._subnet_._cname_:
         result[c.domain[1]].add_host(c.alias[0], c.ttl[0], 'CNAME', c.name[0])
         pass
+    # Add mx hosts
+    for m in tree._host_._interface_._mailhost_:
+        # Force generation of domain file even if only mailhost present
+        result[m.domain[0]]
+        pass
+
     # Add numbered hosts
     def add_host(domain, name, ttl, address):
         if address.version == 4: