Comment 5 for bug 1845751

Mark, regarding this point "It fails to consider whether other DKIM signature breaking transformations such as subject prefixing, addition of headers/footers and content filtering are being done." It checks that no DMARC mitigation is on. In that case, having any DKIM signature breaking is already going to send invalid DMARC email, which seems to me to be a bigger separate problem: I don't think mailman should allow that combination of settings at all: don't send dmarc failing messages. Also, in the case the list has no DMARC mitigation and is breaking DKIM, not modifying the cc here will also prevent mailman from sending as many DMARC failing messages, because it will detect more duplicates and not send them. And, as you said, mailman 2 is going away. So, I think the patch is good as is.