Outlook emails not deliverable to yahoo and aol

It got over my head, so I reached out to support through my admin menu - directly to Microsoft,
They went directly to Godaddy and found errors in the DNS management areas.
They had me copy and paste from my Microsoft DNS records to the Godaddy DNS areas

MX

TXT

CNAME

• its working great now.
  Thanks for sending me in the right direction

Adding to the steps that Jimmy posted which help coming up with the solution, I also found another scenario for a couple of my clients. Both clients in question were not originally setup by me, and when I looked at their domain health in the admin center - Settings - Domains - I found their "onmicrosoft.com" domain was set as default. So when I look at the email message header details, I found a DKIM signature that references the onmicrosoft.com domain, which I believe is contributing to the issue because the email is signed that it should come from an onmicrosoft.com email address, but it is actually coming from their domain address.

So I updated the default domain to the custom domain that they use, but the DKIM signature is still there after about an hour. Not sure if I just need to wait longer, or if I need to do something to force it out. From the message header, this is what I see -

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=XXXX.onmicrosoft.com;

s=selector2-XXXX-onmicrosoft-com;

h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck;

Anyone know if I'm on the right track that this is a contributing factor to the issue? SPF records are correct and in place.

-Brad

EDIT - I also found if you go to the Security Admin Center - Under "Email & Collaboration", click on "Policies and rules", Threat Policies, Email authentication settings, DKIM tab - the clients with the issue had DKIM enabled for the onmicrosoft domain. (whereas my clients that didn't have the issue did not have it enabled). I just tried disabling that for the onmicrosoft domains. I'll give it a bit and re-test.

Here's mine (actual custom domain name erased). Both on the following list are enabled. The default domain in use is our-custom-name.com (not our-custom-name.onmicrosoft.com).

I have no problem emailing yahoo.com addresses. This article should help you decide how to configure your DKIM:

How to use DKIM for email in your custom domain | Microsoft Learn

I have the same issue. All my e-mails to any address at Yahoo are returned to me with the status undeliverable. I use different devices. All my colleagues have the same problem, and we all are using different devices.

I have the same issue. All my e-mails to any address at Yahoo are returned to me with the status undeliverable. I use different devices. All my colleagues have the same problem, and we all are using different devices.

If you are the M365 admin, you should be able to fix it with the steps outlined in this thread. Make sure your SPF (TXT) record is correct, and if you are not using DMARC or DKIM, make sure it is not enabled for the onmicrosoft.com domain as I outlined above. There is nothing that can be done to fix it from the user side, has to be fixed by the administrator.

-Brad