Forensic DMARC reports can be very helpful in identifying unfamiliar sources in your DMARC aggregate reports. Unfortunately, not all domains you are sending to will support sending forensic DMARC reports. This means that even if you know an email you sent failed DMARC alignment, you still might not receive a forensic report for it if the domain you are sending to does not support sending them.
Here is a list of some confirmed domains that will send forensic reports:
We will continue updating this list as we discover more domains that support forensic DMARC reports.