$ORIGIN mydomain.com.
$TTL    7200
@       IN      SOA     ns1 hostmaster (
                        2012072701      ; Serial
                        28800           ; Refresh
                        1800            ; Retry
                        604800          ; Expire
                        86400 )         ; Negative Cache TTL
                IN      NS      ns1
ns1             IN      A       0.0.0.0
localhost       IN      A       127.0.0.1
@               IN      MX 10   mail
imap            IN      CNAME   mail
smtp            IN      CNAME   mail
@               IN      A       0.0.0.0
www             IN      A       0.0.0.0
mail            IN      A       0.0.0.0
@               IN      TXT     "v=spf1 mx"