Build a valid DMARC TXT record for your domain. Choose a policy, add a reporting address, and copy the result into your DNS.
Aggregate XML reports are sent daily or weekly by receiving mail servers. Required to see who is sending email on your domain's behalf.
_dmarc.yourdomain.com. 3600 IN TXT "v=DMARC1; p=none"
DMARC (Domain-based Message Authentication, Reporting, and Conformance) tells receiving mail servers what to do with messages that fail SPF or DKIM checks. A DMARC record is published as a DNS TXT record at _dmarc.yourdomain.com. Start with p=none to collect reports without affecting delivery, then gradually move to quarantine and finally reject once you have confirmed all legitimate mail is passing.
Aggregate reports (rua=) are compressed XML files sent by large mail providers. They show which IP addresses sent mail claiming to be your domain, and whether SPF and DKIM passed. Forensic reports (ruf=) are per-message and contain full message headers - many providers skip them for privacy reasons.