setting dmarc on directadmin zone file in domain

[golfreeze]

I wish to automate new DMARC records for all new domains

If you like the above setup, and you want to automate it's addition to all new dns zones, you can run the following:
cd /usr/local/directadmin/data/templates/
mkdir custom
cd custom
cp ../dns_txt.conf .

and then add the record you want to the bottom of the custom/dns_txt.conf by running this command:
echo '_dmarc="v=DMARC1; p=none; sp=none; rua=mailto:spam-reports@|DOMAIN|"' >> dns_txt.conf

keeping in mind that this assumes you've got a spam-reports account created already.

==reference site
https://help.directadmin.com/item.php?id=596