We sent a message out to our alumni mailing list and got a whole bunch of bounces like this:
The attached message was received as a bounce, but either the bounce format was not recognized, or no member addresses could be extracted from it. This mailing list has been configured to send all unrecognized bounce messages to the list administrator(s).
For more information see: https://xxxxxxxxxxx/mailman/admin/alumni/bounce
From: MAILER-DAEMON@yahoo.com<mailto:MAILER-DAEMON@yahoo.com> Subject: Failure Notice Date: March 16, 2023 at 1:57:17 PM MST To: alumni-bounces@lx<mailto:alumni-bounces@lists.pharmacy.arizona.edu>xxxxxxxxxx
I'm afraid I wasn't able to deliver the following message. This is a permanent error; I've given up. Sorry it didn't work out.
Subject: [Alumni] REMINDER: Join Us | APhA Annual Meeting & Exposition Alumni and Friends Reception
Complete with the weird background color
Strangely EACH and every one of them was a yahoo or AOL address (Yahoo now owns AOL)
Could they be bouncing this based on SPF, DMARC or DKIM issues and just not telling us?
-- Bruce Johnson University of Arizona College of Pharmacy Information Technology Group
Institutions do not have opinions, merely customs