Outlook email Quit working on my Mac suddenly

Question

Outlook email Quit working on my Mac suddenly

Mark Brown 55

Outlook email quit working on my Mac last night and even with an hour of Apple support I can't get it working again.

Rafael Gutierrez 85 Reputation points

2026-02-04T18:55:02.6033333+00:00

On the same boat, cant see any open ticket. Health app is constantly bottering me with statuse that i dont care, but my mac mail app takes a hike and there i no notification from microsoft

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Rafael Gutierrez 85 Reputation points

2026-02-04T18:55:02.6033333+00:00

On the same boat, cant see any open ticket. Health app is constantly bottering me with statuse that i dont care, but my mac mail app takes a hike and there i no notification from microsoft

Answer 1

Rafael Gutierrez 85

In one year, this will happen again. I will have forgotten this. Will try to diagnose it again for 3 hours. And then, when it starts working on its own again... I will remember this.

Microsoft's version of Stephen King's IT

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Answer 2

Hani-Ng 10,395 Microsoft External Staff Moderator

Hi Mark Brown

Thank you for reaching out to Microsoft Q&A forum.

Based on your description, I have checked this on my own environment macOS 15.7.1 Outlook 16.105.2 (26012530) with my business account to reproduce the behavior, but currently, mail synchronization is working correctly for me on both the New Outlook and Legacy Outlook interfaces.

Since I cannot reproduce this locally, this suggests the issue might be specific to how the recent update is interacting with your specific account configuration or cache.

Here are some recommendations from me you can try:

Test via Outlook on the Web (OWA)

Please open a web browser and sign in to outlook.office.com (or your specific provider's webmail)

If you cannot sign in here: The issue is with your account status, password, or server (not the Mac app). You may need to reset your password or contact your IT admin.
If you can sign in here: Your account is healthy. The issue is strictly isolated to the Outlook for Mac application.

Switch to "Legacy Outlook" temporarily

Many sync issues affecting the "New Outlook for Mac" can be temporarily bypassed by switching versions. If this works, it indicates a compatibility issue between the "New Outlook" architecture and your email provider.

If you are unable to access your email on either version, or if the Web App works but the Mac App does not work completely, this needs to be aware by Microsoft engineering team for a patch by posting similar behaviors and submit Feedback directly,

Go to Outlook > Helps or you can go to direct via here.

This sends the logs directly to the product team. If you see existing feedback regarding your issue, please Vote Up that feedback.

Additionally, I hope you understand and note that this is a peer-to-peer support forum. I'm a fellow user and am offering advice based on my own research and Microsoft's published documentation.

I hope my information helps

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Mark Brown 55 Reputation points

2026-02-05T01:22:32.3966667+00:00

I do not understand any of this. My Outlook account was working fine yesterday and today it is not. It works on the iPad and iPhone but not on the Mac. I can log into it using the web but not using Mail. Makes zero sense.
Travis T 10 Reputation points

2026-02-05T01:44:19.2+00:00

Hang-Ng.

This does not appear to be a My Outlook issue. It is also happening to a select number of MacOS Email accounts. Here's what I posted in another thread after working on this issue all day today. Please help escalate this issue to the right technical folks.

Ok. So I have same problem as everyone else on this Thread today. My last successful email came in at 9:08pm on 2/4/2026. I see this thread started about 12 hours before my issues.

I've done a bunch of testing today and here's what I know.

I have 5 Godaddy emails for various things on my MacOS Big Sur 11.7. 2 of the 5 stopped working with the error…

Connections to host (null) on the default ports failed.

3 emails continue working on MacOS Mail. 2 Broken ones have the triangle.

Email provider is Godaddy which sends us all now to Microsoft Exchange Mail.

Connection doctor on Mac can't ever get to the server. Tried deleting one of the broken accounts from MacMail and re-adding. Same issue. Have tried everything, removing hidden keys, checked for viruses, rebooting, updated MacOS to latest version of Big Sur (11.7.11), tried to manipulate manual exchange settings nothing. Tried deleting one of the 3 working email accounts in MacMail and re-adding. This worked fine for a previously working email.

I can successfully access the 2 MacMail broken email accounts via Web Login to Exchange fine. iPhone access to the broken emails continues to work fine and never stopped working for the 2 broken accounts.

The 2 broken accounts are on the same domain. I've tried other emails on same domain in MacMail and they are fine.

Went home and got on my iMac with latest Sequoia 15.7.3 that is a relatively new build and has never had any email accounts on it. When adding these 2 Broken emails to this Mac they still don't work on a fresh machine with the latest version of MacOS. Emails that work on other machine work just fine in MacOS mail on the home machine when added.

Bottom line. I believe that I've eliminated enough variables to determine this is likely NOT a Mac issue. It is a Microsoft Exchange problem. There appears to be an issue somewhere deep in the Microsoft Exchange code somewhere that breaks some emails with some particular setting. The fact that 2 of my 5 are not working and others are posting it must be fairly widespread. -- but only with MacMail users.

MICROSOFT HELP INVESTIGATE AND SOLVE THIS PROBLEM!!!

Any idea from anyone on how to get Microsoft's attention on this?

Thank you.
Mark Brown 55 Reputation points

2026-02-05T02:08:14.61+00:00

Travis, thanks for posting this as it desciñes my issue perfectly. I wish MSFT would have support with humans like Apple does!
Hani-Ng 10,395 Reputation points Microsoft External Staff Moderator

2026-02-05T05:30:18.4166667+00:00

Hi Mark Brown; Travis T

Thank you for your detailed description.

First, I hope you understand that this is a peer-to-peer support forum. I'm a fellow user and am offering advice based on my own research and Microsoft's published documentation.

Based on what you described, after doing some research I understand this may be an intermittent issue. I found that some users have also experienced intermittent problems with Mac Mail and Exchange, and in most cases the issue was resolved after a few days.

Here are some situations as reference you can see: (Although the error symptoms are not identical, they all appear to be intermittent issues)

Unable to add Exchange email address in Apple Mail on Mac - Microsoft Q&A

Unable to add my hotmail addresses to imac - Microsoft Q&A

Apple Mac Mail无法添加我的Hotmail和Outlook账户 - Microsoft Q&A

(Please note that the resource linked in this thread is available exclusive Chinese. I sincerely apologize for any inconvenience this may cause to those who prefer or require content in English. If you need assistance understanding the content, I recommend using a trusted translation tool or service)

In your situation, since the accounts were purchased through GoDaddy, as you mentioned they cannot provide direct support. However, you can ask GoDaddy to help you create a support ticket via the M365 admin center on your behalf if you would like to reach out to the Microsoft support team.

I hope this information helps.
Mark Brown 55 Reputation points

2026-02-05T12:03:54.6733333+00:00

I don't know what changed overnight but my Outlook account is now working through the Exchange!
Bonyo Bonev 60 Reputation points

2026-02-05T12:16:04.1366667+00:00

Same here, overnight everything was fixed so apparently reverted some patch
Bonyo Bonev 60 Reputation points

2026-02-05T15:11:20.07+00:00

I think it is almost there but synchronization is kind of slow and buggy. I got all my old mail but new one is popping slowly and requires connection refreshes.
Travis T 10 Reputation points

2026-02-05T17:34:28.19+00:00

Same here. All working this morning. There's 6 hours intense debugging I'll never get back.
Hani-Ng 10,395 Reputation points Microsoft External Staff Moderator

2026-02-06T05:58:18.6966667+00:00

Hi Mark BrownThank you and everyone for the updates, and I’m very glad to hear that everything is working,

Have a nice day!

Answer 3

Rafael Gutierrez 85

On the same boat, cant see any open ticket. Health app is constantly bottering me with statuse that i dont care, but my mac mail app takes a hike and there i no notification from microsoft

Hani-Ng 10,395 Reputation points Microsoft External Staff Moderator

2026-02-05T05:34:35.6233333+00:00

Hi Rafael Gutierrez

Could you please let me know which type of email you are using? If you are using a business account, you can refer to this document to open a support ticket with the Microsoft support team: Get support - Microsoft 365 admin | Microsoft Learn

Thank you!

Answer 4

Bonyo Bonev 60

Same here. Nothing resolve it. New user account, deleting-adding, keychain authentication removal.... nothing. iOS works ok, macOS mail not. Exchange Calendar for that account works just fine on macos.

Bonyo Bonev 60 Reputation points

2026-02-04T18:26:40.1+00:00

not sure if it helps but the issue that macos mail is reporting is:

Connections to host (null) on the default ports failed.

Nothing on my end have changes, restarted firewalls and etc nothing helps and I am the only one with mac in the office. The PCs does not have this issue. Right now I am working via Safari on the Web but this needs to be resolved on MS end.
Mark Brown 55 Reputation points

2026-02-04T18:56:30.1666667+00:00

This just happened last night. My Exchange email works fine but the Outlook email will not work on the Mac. It does work on the iPad and iPhone. Spent an hour with Apple support and they couldn't fix the issue.
Bonyo Bonev 60 Reputation points

2026-02-04T18:58:29.6233333+00:00

same here. It worked last night and today when I came to the office it does not. This is 100% MS issue on the backend with authentications.
Mark Brown 55 Reputation points

2026-02-04T19:01:10.6533333+00:00

Do you know how to resolve it? You can't talk to a human at MSFT from what I can discern. Unlike Apple support that is very easy to get on the phone.
Bonyo Bonev 60 Reputation points

2026-02-04T19:09:09.6733333+00:00

Unfortunately no resolution from our end. I tried everything from removing-adding account, restarting, deleting all authentication stuff from Keychain, creating even a new account and testing it there produced exactly the same issue. So no, I do not believe this is solvable at this moment from our end. It smells like MS updated something overnight and it broke the authentication. Now there are 2 resolutions - MS revers back or we wait until Apple updates Mail to be compatible with the new stuff. Either way it sucks.
Bonyo Bonev 60 Reputation points

2026-02-04T19:09:57.5533333+00:00

the only option now is accessing the mail account on the web!
Mark Brown 55 Reputation points

2026-02-04T19:53:44.9966667+00:00

yes that's the only way i can access Outlook now. I am signed in on a PC now that used to have the Outlook account and it is gone there as well. Very strange!

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Outlook email Quit working on my Mac suddenly

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