firewalled_smtp: driver = smtp port = 1234 firewalled_hosts: driver = lookuphost transport = firewalled_smtp domains = foo1.my.com:foo2.my.com:foo3.my.com
driver = smtp port = 1234
firewalled_hosts:
driver = lookuphost transport = firewalled_smtp domains = foo1.my.com:foo2.my.com:foo3.my.com