New Outlook Windows App Opt-in Option Unsupported Features

While New Outlook for Windows is available to the end users as an opt-in option, we strongly recommend using Outlook Classic as a main client because of existing limitations.

To date, there is no official statement from Microsoft regarding the discontinuation or removal of the Outlook Classic application. You can continue to use it as usual.

New Outlook for Windows known limitations:

Feature Missing 


Approximate Rollout date 

Cannot open .eml, .msg, and .oft files 

Support for opening email files saved to a user’s file system with .eml, .msg, and .oft extensions.

Late March – Late April 2024

Cannot connect PST archives 

User cannot access email archive (PST files) with New Outlook client.

“Coming soon”
(no dates available)

No option to create different Outlook profiles 

No option to create different Outlook profiles


No option to manage room resource calendar permissions 

New Outlook does not allow users to change permissions in shared calendars.


Multiple domain aliases support 

Some issues were reported using multiple aliases on their mailbox (e.g.,


For more information on the features of Classic vs. new Outlook please refer to the Outlook version comparison chart.