Factsheet
PSA: New Outlook will be forcefully installed on Windows 10 with Feb 2025 Cumulative Update
New Outlook app for Windows use 10 times more ram, 20 times more CPU, and has much slower startup time. : microsoft
Outlook 365 on Windows 10 MU as Virtual App
Are you using FSLogix? What profile mgr you using?
More on reddit.comWindows 10 KB5051974 installs Outlook web, replacing Mail & Calendar apps
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Report from Bleeping Computer:
https://www.bleepingcomputer.com/news/microsoft/microsoft-to-force-install-new-outlook-on-windows-10-pcs-in-february/
Officiall Microsoft doc:
https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/get-started/control-install#block-new-outlook-preinstall-on-windows
This has become a bigger problem in the last few days. Previously you were able to opt out, but that's no longer the case. So, until I decide which 3rd party email client I want to commit to, I've came up with a work around.
The premise is if the new Outlook client isn't installed then Mail will launch normally. So, I created a batch script that uninstalls the new Outlook before it launches Mail.
POWERSHELL -ExecutionPolicy Bypass -Command "Get-AppxPackage | Where-Object {$_.Name -Like '*OutlookForWindows*'} | Remove-AppxPackage"
explorer.exe shell:appsFolder\microsoft.windowscommunicationsapps_8wekyb3d8bbwe!microsoft.windowslive.mail
There's no way to know how long this will work... I expect Microsoft's next step will be to remove/blacklist the Mail app altogether.
Additional Details Requested...
I'm running Windows 10, YMMV.
The other method finally stopped working for me, probably due to a Windows update.
The two lines above are the entire contents of the .bat file. I prefer to see the CMD window popup, as it gives a quick notification about the uninstallation, but then exits automatically after the exploere.exe (Mail) process is started.
The batch script, Open Mail.bat is saved in %homepath%.
I then created a shortcut, Right Click > Send To > Desktop (create shortcut) and moved the resulting .lnk file to %appdata%\Microsoft\Windows\Start Menu
(Additionally, I changed the icon for the shortcut in it's properties.)
The shortcut, Open Mail, is now visible in my Start Menu so I'm able to Pin to Start, and put it where I normally pin the Mail shortcut.
This script does the Outlook uninstall and Mail launch... so it is run to launch Mail, instead of clicking the Mail shortcut directly (doing so will result in opening Outlook, in my case.)
Because the *-AppxPackage commands in the script omit the -AllUsers option, it only applies to the current user and elevated privileges are not required (i.e. Run as administrator is not needed).
...Then Outlook will be reinstalled automatically, Mail will present the "Dismiss" message at the top... and the next time I need to run Mail I click on Open Mail again.
I can't use the Outlook Desktop App because it doesn't support Exchange ActiveSync.
I've had to do the following several times. (Every time Windows updates it re-installs Outlook) and eventually this workaround won't work (End of year). This is the simplest way I've found to get Windows Mail working again:
- Go to Settings -> Apps -> Installed Apps.
- Find and uninstall Outlook.
At this point if you try to use Windows Mail it will still just shut down as soon as you open it.
While still in Installed Apps, scroll up to Mail and Calendar.
Click on the three dots and choose advanced options.
Scroll down and choose reset (not repair)
After it finishes resetting, close Settings and open Windows Mail and wait a few seconds.
A box will pop up "Allow Mail to access your calendar"? Choose YES.
Then another box "Allow Mail to access your contacts" Choose YES.
Then another box "Allow Mail to access and send emails? Choose YES.
(These three boxes have been in random order on some resets. Just answer YES to all three.)
Then you'll get a message "Outlook is replacing Mail and Calendar" Choose "Not Now"
I've done this several times and each time, my email account reappeared in Windows Mail with no information missing. This avoids having to download and re-install the Windows Mail App, AND having to add your email account back into the App.