MacOS email client with O365
Posted by Great-Examination664@reddit | sysadmin | View on Reddit | 37 comments
Hello friends, I have one Mac user who is the type that doesn't even want to hear about Windows. However, our ecosystem is on Windows. Let me describe the problem: the user has the organization's email (Exchange) set up on the macOS Mail client and works happily until she decide to delete an email. As soon as she delete an unnecessary email, the following warning appears: image
Has anyone encountered something similar? I've searched through all the forums but haven't found a solution yet?! thanks
tejanaqkilica@reddit
Your ecosystem is Windows and you provided this single user with a Mac?
Why? Do you hate yourself?
Shazam1269@reddit
Right? We've had supervisors push for using their Mac in our Windows environment, and the answer is always NO.
devonnull@reddit
Really? I enjoy explaining that they won't have admin anymore...I love that look that they get.
PizzaUltra@reddit
So they have admin on windows devices, but won't have admin on mac devices?
Ihaveasmallwang@reddit
Why is this one user dictating anything?
rthonpm@reddit
Because plenty of Mac users think they're special.
Ihaveasmallwang@reddit
Plenty of mac users don’t.
This is a failure from a lack of organizational standards regarding user equipment and software.
Even if the organization were allowing different hardware vendors, this is a failure from not enforcing an approved client to access email. They should have already blocked this in their security policy.
devonnull@reddit
Oh...dearie...that's so sweet. I remember being young and naive as well.
Ihaveasmallwang@reddit
By young and naive you mean working in this profession for decades, sure.
It’s ok to tell the user “no” sometimes, especially when you can back it up with well defined company standards instead of an immature we let people do whatever they want approach.
adamphetamine@reddit
I'm a Mac guy, but we now tell people
'Mac Mail should work with M365, we can't guarantee any specific feature will work- or that issues will get fixed'
Great-Examination664@reddit (OP)
I get your point, but look - we're talking about someone whose technical skills end at pressing the power button. They just fold the laptop when they're done and have never actually hit 'shutdown.' Explaining what you just said to someone like that is a real challenge.
thisguy_right_here@reddit
"I looked into it and a mac mail issue. The advice is yo use Outlook app or OWA. Lmk if you want to live with the issue or want me to install Outlook for you"
sloppy_cement_farts@reddit
That is one of the tasks and challenges in IT work. It only gets easier the more you do it and find ways to articulate it properly.
Frothyleet@reddit
Show them how to access OWA in Safari or whatever browser they use, let them know that's the supported method and you don't have the ability to further troubleshoot Mac Mail.
aguynamedbrand@reddit
Stop catering to individual users.
bjc1960@reddit
How do these people have jobs in 2026? In one decade is "I'm not technical" no longer an excuse? We have similar issues- people need a calculator with a paper tape to add numbers in Excel as they can't/won't leave 'addition' in Excel.
adamphetamine@reddit
ok how about 'you can use it, but I'm not fixing it'
Electrical_Bad2253@reddit
Tell the user you have a new policy that no email is allowed to be deleted.
lesusisjord@reddit
I’ve gladly been following that policy for decades!
CFH75@reddit
I have users that use Mac mail with m 365. Maybe they need to update their os.
devonnull@reddit
Oh they can't be bothered with that...don't you know that the new update breaks their precious workflows and you're an IT meanine for suggesting that THEIR Mac (but it's company owned) needs to be updated as it's OBVIOUSLY a network problem?
LibDucGeek@reddit
I had the same issue crop up. Outlook for Mac is going away, and warnings pop up every few times it opens.
My solution was to download MS Edge for Mac, sign into the browser using their MS365 credentials, and use Outlook online.
They dislike it until you offer them a Windows machine. Then they deal with e-mail through gritted teeth.
Twuggy@reddit
I'm lucky that my org is mature enough to have a bespoke list of apps that are supported.
Native mail apps are not supported. Apple or the Web page pretending to be an app that is the native Windows mail app.
hazeleyedwolff@reddit
So no new Outlook either?
Evil-Bosse@reddit
Which of the new outlooks are we talking about? New outlook, new outlook 2026, outlook(new), new outlook by copilot, new outlook(new), new new outlook(classic)?
hazeleyedwolff@reddit
"I have two outlooks, and neither of them work."
babywhiz@reddit
That is what the last item Twuggy was talking about.
RAVEN_STORMCROW@reddit
Not that abomination
aew3@reddit
If you have O365 why not outlook for macos?
aguynamedbrand@reddit
Does the issue present itself when using Outlook? If not then there is your solution.
Also, remove Apple Mail client from your approved software list if you are having issues with it.
The_Real_Meme_Lord_@reddit
Available for use, unsupported for functionality
ArchonTheta@reddit
The native macOS Mail app’s Exchange compatibility has always been patchy. It uses EWS, and Microsoft has been deprioritising EWS support in favour of Graph API for years. If this user wants to stay on Mac but needs reliable Exchange behaviour, Microsoft Outlook for Mac is the practical recommendation. It uses native Exchange/Graph connectivity and behaves far more predictably than the built-in Mail app for O365 tenants. The free Outlook for Mac is available via the Microsoft 365 web download or via the App Store.
VB0101@reddit
I've seen this error before, I can't exactly remember what I did off the top of my head, but I'm pretty certain I just deleted and rebuilt the Mail cache. A relog might just solve the issue as well.
SquashNo7817@reddit
Correct. In the worst case I had to remove that local user account. Create a new one. All is fine.
My guess is that user upgraded from some ancient version. Apple mail is hopeless for large mailboxes (and in every large version upgrade it changes the format).
purplemonkeymad@reddit
In my experience mac mail is fine with exchange accounts that have a few thousand in the mailbox, but just dies after some set number of emails. We tell people to use Outlook for Mac or webmail instead.
Borgquite@reddit
Have you tried removing the account from the Mac and adding it back in again?
SwedenNr1@reddit
Unfortunately I do not know about this specific issue. But we had a few issues with people using the iOS default mail app. After a user accepted a meeting invitation it re-sent the acceptation-email every 2-3 minutes 24/7. The solution? Have them remove their work account from the iOS mail client and install Outlook instead.
So I guess my suggestion is just that, atleast have him use the tailored applications if he wants to use a different OS.