There are two different tactics to take if you do not want the same policy level on a parent domain’s subdomains:
1. Create a DMARC record for any subdomain and specify the policy level you require.
2. Use the sp= tag on your parent domain’s DMARC record to specify what policy level you would like your subdomains to have, rather than inheriting from the parent domain.
For example, you can add sp=none to the parent domain’s DMARC reject policy so that none of your subdomains inherit the reject policy until you are ready to implement it. In this case, a full record example would look like the following:
v=DMARC1; p=reject; sp=none; fo=1; rua=mailto……..
In GlockApps DMARC Analytics, you can specify a different DMARC policy for your subdomains and the tool will include the sp= tag with the specified policy to your DMARC record.