In article <CAPt1N1=_jvrNbhxDyWXpJszUtqRZEEouRibwgWD1aY5wfhsX_Q@xxxxxxxxxxxxxx> you write: >There's a pretty clear ops problem here that could be solved by simply >detecting addresses with DMARC and rewriting the From: headers on >those messages. This would eliminate all problems immediately. Assuming you mean replacing the actual author's address with the list's address, that has the cost of breaking the way mailing lists have worked for 30 years, and in particular making replies to the author unworkable. Many people would strenously disagree that this "eliminates all problems", but merely replaces one problem with another. There are other workarounds with different costs and benefits, e.g., the one I use that rewrites DMARC'ed addresses into local temporary forwarding addresses, in my case in the trendy dmarc.fail domain. That lets people keep using lists the way they have but requires more mail system hackery than most list managers are able or willing to do. Again, this has been discussed at great length here and on many mail-related lists. Please see the archives. R's, John