FYI, I'm just using a Yahoo email account (via web interface) to post to the Mailman-users list. I don't use this account for much anything else.
All posts to the list in question are moderated and almost all are sent from a Mozilla Thunderbird email client.
And almost all subscribers (including AOL subscribers) are set for digest mode.
In the list mail the from line always shows the listname@subdomain.domain1.org (not an individual email address or freemail domain)
How do I find these DMARC workarounds which you speak?
On Fri, 12/4/15, John wrote:
I see that you have a yahoo.com address. If there's a yahoo.com address on the From: line of the list mail, AOL and Yahoo's well documented abuse of DMARC will cause the failure you're seeing.
If you're running a recent version of Mailman, there are some DMARC workarounds you can use. Other than that, I'd find a different address to mail from, not at Yahoo, not at AOL, and preferably not at Gmail.