Date: 4/16/26 2:45 pm From: David Scheu <00000454f801cafe-dmarc-request...> Subject: FW: LISTSERV FROM address changes on 4/24/2026
MOBirders,
I am forwarding an email I just received from MU IT, who hosts our list server. Full announcement is below, but the digest version is, email return addresses are being obfuscated in order to prevent mail from the list ending up in spam folders, which is something that has happened to me, and I know has happened to others. I have been told in the past there's nothing that they can do on the server side, but apparently the problem got bad enough that they figured out something they could do. I know some of you have already managed to fix the problem from your end, but hopefully this change will help mail get through to everyone, and the strange return addresses will not be too off-putting or confusing. We'll have to see how it goes!
Thanks,
Dave Scheu
MOBirds-L list co-owner
St. Louis, MO
From: Walker, Brand <walkerbr...>
Sent: Thursday, April 16, 2026 2:53 PM
To: <ALL-REQUEST...>
Cc: UM - IT Email Server Team <cloudservicesteam...>
Subject: LISTSERV FROM address changes on 4/24/2026
On Friday, April 24th we will change how FROM addresses work with LISTSERV messages. This will apply to everyone who sends mail through our LISTSERV lists.
You may want to brief your Subscribers, so they are not surprised on the 24th.
Users will notice that mail shows a different FROM address going forward. The Display Name will not change. Mail from "John Smith" will still say "John Smith".
However, an address like <user...><mailto:<user...> or <person...><mailto:<person...> will be changed to something like <00000003f16b4808-dmarc-request...><mailto:<00000003f16b4808-dmarc-request...>.
People will see that new FROM address. Some of them will ask questions.
NOTE: If your list has message archives, the archives will show the original FROM address.
P.S. - Why are we doing this?
Most Subscribers don't need this much detail, but you deserve to know. Nobody is at fault here. New email protections require us to make a change, so our mail will deliver. That's the situation.
Mail to some recipients recently started bouncing back to us with this new error message:
Access denied, sending domain MISSOURI.EDU doesn't meet the required authentication level. The sender's domain in the 5322.From address doesn't meet the authentication requirements defined for the sender.
The underlying problem: Email services are starting to roll out new email protection rules. If the FROM address does not align with the list address (lists.umsystem.edu), our mail gets rejected.
For example, FROM:<walkerbr...><mailto:<walkerbr...> does not align with lists.umsystem.edu. Mail from umsystem.edu does align and pass, but we cannot ignore the other campuses. This problem also applies to mail from our external Subscribers.
We can send into a list just fine. The trouble comes when the list tries to deliver. So far, we've seen bounces reported from HOTMAIL.COM, LIVE.COM, MSN.COM, and OUTLOOK.COM. None of our LISTSERV mail is reaching those Subscribers. That list is probably incomplete today. Plus, more services will implement rules like these over time.
For technical reasons, we cannot address these bounces on a case-by-case basis. This must be a global change on the server.
Brand Walker
Division of IT, University of Missouri
<walkerbr...><mailto:<walkerbr...>
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