$ORIGIN example.com.
$TTL 1h
example.com. IN SOA ns.example.com. username.example.com. ( 2007120710 1d 2h 4w 1h )
example.com. IN NS ns
example.com. IN NS ns.somewhere.example.
example.com. IN MX 10 mail.example.com.
@ IN MX 20 mail2.example.com.
@ IN MX 50 mail3
example.com. IN A 192.0.2.1
IN AAAA 2001:db8:10::1
ns IN A 192.0.2.2
IN AAAA 2001:db8:10::2
www IN CNAME example.com.
wwwtest IN CNAME www
mail IN A 192.0.2.3
mail2 IN A 192.0.2.4
mail3 IN A 192.0.2.5