I played with DMARC about a year ago. I put it in monitoring mode so that I'd get email reports from systems to tell me when they received emails from my domain

I played with DMARC about a year ago. I put it in monitoring mode so that I'd get email reports from systems to tell me when they received emails from my domain which failed DMARC. I started getting them from all over the place. Pretty much all related to mailing lists breaking the DKIM signature by rewriting headers or the body. My conclusion was: If any email address on your domain subscribes to one or more mailing lists, DMARC will break your email. I disabled it. I don't see myself enabling it again any time soon.