The people who designed DKIM didn't care about how mailing lists worked, they just did it anyway. But Mailman has adapted over the years, and Mailman3 is greatl

The people who designed DKIM didn't care about how mailing lists worked, they just did it anyway. But Mailman has adapted over the years, and Mailman3 is greatly improved. IMO, it's the best mailing list package out there, especially with regards to DKIM and DMARC compliance, but only if it is configured correctly. However, even that can only carry you so far. Gmail is screwed up in how they handle reputation, especially with regard to IPv6. The exact same message delivered to Gmail via IPv6 will get refused versus sending it via IPv4 will work fine. This problem has existed for years. There are even standard hacks for postfix to cause all mail addressed to Gmail to be sent via IPv4 only, just to avoid this problem. And any domain hosted with GAFYD is likewise screwed. You can't know what your false positive stats are, because you don't have access to all the remote SMTP spools or logs on the 'net. All you can know for sure is the false positives that you find out about. But you literally have no way to tell how big the iceberg is under the water.