DNS Server

$ORIGIN mydomain.custom.
$TTL 2h

@               IN  SOA    ns1.mydomain.custom. myemailaddress.gmail.com. (
                                 1000000000 ; Serial
                                 8h         ; Refresh
                                 30m        ; Retry
                                 1w         ; Expire
                                 1h )       ; Negative Cache TTL
                NS      ns1.mydomain.custom.

@               A       127.0.0.1

www             A       127.0.0.1

ns1             A       127.0.0.1

mail            A       127.0.0.1
imap            CNAME   mail
smtp            CNAME   mail