Outlook Support From You All

Posted by WineFuhMeh_@reddit | sysadmin | View on Reddit | 19 comments

Everyone,

I could use some help when it comes down to the New Version Of Outlook.

Problem: On Outlook New, when user is getting new mail she has to keep clicking "Sync" For it to populate in her inbox.

Troubleshooting I've Done

- Uninstall, Reinstall to latest version of outlook, triggered new issue still presists.

- Gave the user a new macbook M5, on Tahoe issue still preisist on both old and new laptop at home

- Reset user password, update MFA methods, verify user account is in good standing, checked UPN and Principal Names, Along with Licensees

- Attempted to have the user connect to a mobile hotspot to isolate it to being a network issue still preisists

- Dumped outlook cache, removed caches, reset account.

Reverts to outlook legacy... eveyrthing works smooth, and OWA works smooth as well.

At this point i'm trying to figure out how to get the user back on to the new version of outlook i'm out of troubleshooting steps.

Security Stack.
Crowdstrike, illumio, Tanium, Rapid7, GlobalProtect. (YES, I uninstalled all of them) Issue still happens

MDM

Jamf Pro

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WineFuhMeh_@reddit (OP)

Yea even on prem or on vpn (with different regions) it’s the same issue.

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Googling suggests this has been a problem since early 2025 - looks like they haven't identified the source of the problem in all cases. You may have to roll them back to the true Outlook client aka in MS parlance "Old" outlook. The "new' client is a complete ground up rewrite it seems and appears to have bugs galore in it.

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WineFuhMeh_@reddit (OP)

Nope, it’s not a shared mailbox. But it’s interesting to think that the issue is happening with a shared mailbox…

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WineFuhMeh_@reddit (OP)

You’re right it’s both M365. And one account being set as default. I did confirm no IMAP or POP configuration.

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incompletesystem@reddit

I got nothing. Sorry

Sack the user and go for a coffee.

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WineFuhMeh_@reddit (OP)

Tell me something I don’t know. But this executive she’s like attached to it…

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R3luctant@reddit

Because it's applefied.

Hornblower409@reddit

Duplicate of

https://www.reddit.com/r/MicrosoftOutlook/comments/1smris2/requesting_some_kinda_of_support/

https://www.reddit.com/r/Office365/comments/1smrs2k/outlook_support_needed/

Next time - The best way to cross post on reddit is to Click on the [Share] button under your question and choose -> Crosspost. So all of your cross post link back to the original and any comments are all in one place for everyone to see.

Does the issue also occur when the user is in the corp network? As you mention it still persists when at home or using mobile hotspot.

KelyK70@reddit

I am literally working on a presentation/training for New Outlook right now because it’s so bad and everybody hates it. Is this users inbox a shared inbox.? If it is, that is a known issue with new Outlook. Syncing has to be done manually for shared inboxes.

-sharkbot-@reddit

Dude I had one user who could not get the KnowBe4 phishing button to work in outlook. Just goes to click submit and forever spinning circle.

Different network, vpn/no vpn, pulled the app from deployment + redeployed, online version + desktop version, reset her outlook, dumped every cache, nuked her keychain. Hopped on a brand new laptop we had just to test. Nothing worked. Sent packet captures to Microsoft and knowbe4, they clearly didn’t know what to ad wrong as they were telling me to redeploy. Every single other person in the company doesn’t have an issue with it. Why ONLY her mailbox? She’s not the oldest employee, she shares permissions with other lab users, no special role. Like what the fuck?

I swear that sometimes Outlook accounts just get corrupted somehow. We had her login to another account on the same device and it worked flawlessly. So weird, still need to get back to support about this but I’m so spent trying to fix this with her and she just forwards anything phishy in the meantime.

That suggests a configuration setting used by the client and stored in the mailbox is the problem - you might need to dump the mailbox data from the mailbox to see if it resolves it.

What mail service is it connected to; and how its it connected?
I'm guessing its Microsoft 365 and its using the default/native connection.

and not POP or IMAP? (I've seen people do this because thats how it used to work in 1992).

Jug5y@reddit

Just use classic

DWC-1@reddit

Your troubleshooting routine was wrong. Here is the improved version:

- Uninstall~~, Reinstall to latest version of outlook, triggered new issue still presists.~~

Ask NASA:
https://x.com/MarcusHouse/status/2039579997976121779

Man, I hate new outlook.