Hmm. The headers on the message I got are in the attached text file, and they are all absolutely hunky-dory at first glance. No reason for mailman not to share the message with list members, no reason for the outgoing message to be blocked, no reason for the recipients to spam-bin it. More thought apparently needed. Pondering, Nico From: Andrew Price via Selenetest &lt;selenetest(a)lochac.sca.org&gt; Sent: Wednesday, 4 May 2022 10:01 PM To: selenetest(a)lochac.sca.org Subject: [Selenetest] Test yahoo Test message Sent from Yahoo Mail on Android <https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub2=Global_YGrowth&af_sub3=EmailSignature>