Dmarc

v=DMARC1;p=reject;sp=quarantine;pct=100;rua=mailto:rua@example.com;

v=DMARC1;p=reject;sp=quarantine;pct=100;rua=mailto:rua@example;

 If your DMARC record was previously:

v=DMARC1; p=none; rua=mailto:example@domain.com; ruf=mailto:example@domain.com;

Your optimized DMARC record will be:

v=DMARC1; p=reject; rua=mailto:example@domain.com; ruf=mailto:example@domain.com;

Or, v=DMARC1; p=quarantine; rua=mailto:example@domain.com; ruf=mailto:example@domain.com;

Receive for external domain

Example

https://www.contoso.one/2018/09/setting-up-email-for-parked-domains.html#ExternalAuth

Add these to your receiving domain if receiving rua reports for example.com domain.

example.com._report._dmarc   TXT "v=DMARC1" 
*.example.com._report._dmarc TXT "v=DMARC1"

More links

https://serverfault.com/questions/889691/why-my-dmarc-are-not-giving-permission-for-reports

https://dmarc.org/2015/08/receiving-dmarc-reports-outside-your-domain/

https://powerdmarc.com/dmarc-policy-not-enabled/