How can I mount a data file (pst) in new outlook. In the classic version this is doable through the File menu which is not available in new outlook.

Microsoft have announced that the new Outlook will be forced on users from January 2025. If they have not fixed this issue by then it is going to upset considerably more users. What really grind my gears as a system admin is we have to support users who will complain to us about missing functionality and then we blame Microsoft for dishes out this pile of <Bleep>. As an Sysy admin we are then expected to jump through hoops to enable this, disable that.

https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/get-started/control-install

If the MS Product Managers are monitoring this thread (and they should be fired if they aren't), let me give you a lesson in your job (no charge).

People use products because they like them, and they continue to use them because of feature continuity. They build business operations around those capabilities, and they accumulate assets (i.e. historical data, retained emails, their calendars, etc) which are VALUABLE to them, to their business. They are reluctant to change, disrupt if you prefer, their lives and businesses by changing to a different system because it involves new ways of working and, often, the loss of integrated use of that historical asset - their data. That is, or SHOULD BE, a competitive advantage for you. Call it inertia, resistance to change, incumbent advantage, whatever.

WHEN YOU INTENTIONALLY THROW AWAY THAT ADVANTAGE, like you have done here, then it is MUCH easier for us to leave and start using Google Workspace, or Thunderbird or Evolution. Whether we stay with you or spend our money with someone else, we have the inconvenience/hassle/aggravation either way. BUT, you have MOTIVATED US to leave, so in some ways you have put yourself at the bottom of the list of options. So, can you give us any reasons why we SHOULDN'T just take our business elsewhere? Because so far, I haven't seen any.

Microsoft will NOT be replacing Classic Desktop Outlook until at least 2029:

"Please note that the cutover stage does not signify the end of support for classic Outlook for Windows. We will continue to honor published support timelines for existing version of classic Outlook for Windows until at least 2029."

New Outlook for Windows: A Guide to Product Availability | Microsoft Community Hub

Interesting. Coming soon as of March 28, 2024 (and probably earlier). Here we are in January of 2025 and still "coming soon". Wonder what "soon" means to Microsoft.

If it’s anything like their progress bars and install timers ‘soon’ could mean absolutely anything.