$TTL 1h
@       IN      SOA     {ns1}. {ns2}. (
                        2024120301      ; Serial number
                        1h              ; Refresh interval
                        15m             ; Retry interval
                        1w              ; Expire interval
                        1h )            ; Minimum TTL

@ IN NS      {ns1}.
@ IN NS      {ns2}.

ns1     14400     IN      A       {server_ip}
ns2     14400     IN      A       {server_ip}

{domain}.     14400     IN      A       {server_ip}
{domain}.     3600     IN      MX       0 {domain}.
www     14400     IN      CNAME   {domain}.

mail    14400     IN      CNAME   {domain}.
webmail    14400     IN      CNAME   {domain}.

{domain}.    14400     IN      TXT       "v=spf1 ip4:{server_ip} +a +mx ~all"