How to Open a .PST file from the new outlook. File menu disapeared

I completely feel for you all. I too hope that PST files will be supported in the new Outlook soon. Just to add:

It should be no problem to use both versions. I have both versions installed and run them in parallel. Don't use the switch button top-right, just start both and run both. I still mostly prefer "old", but I go to "new" to use Copilot features. I switch seamlessly. If I delete a mail in "old" it is instantly gone in the "new". Aaand I mount PSTs in the old.

This won't work if you use POP3, but then, really you need to step up. POP3 was a grossly outdated technology 10-20 years ago.

With a 365 or outlook.com/hotmail.com/live.com mailbox, it is no problem. With IMAP it should work too.

Microsoft is notorious for keep old technology propped up on adderal like an American president. So expect old Outlook to be available for a long time, at least two-three years I would guess.

But: All good things must come to pass. Outlook is based on code and technology from the 90s. One must expect it to die. No software lasts forever. PSTs are a totally proprietary format, so having a lot of business critical data stored in PSTs is a bit of a gamble. Anyone with half a tech brain would have known 10+ years ago that this day would come eventually. That is the difference between open and proprietary data formats. ZIP files or JPEGs or PDFs will forever be possible to open, because the formats are open. If you need someone to share your grief, and have a time machine, go back to the 90s and talk to e.g. those with Word Perfect or dBase files they couldn't fully read.

OTOH, like with WP and dBase files, expect a) Microsoft to provide means to import PST archives to the "cloud" (they already do), and b) 3rd parties to reverse-engineer the format and sell inexpensive apps to let you open those old PSTs (they already do).

this sucks, I need this function now

This is disgraceful - I too have lost years of critical business and personal data. At the very least Microsoft should have in-built data conversion.

I asked Microsoft copilot and it replied with a long list of reasons why PST files will never be supported. I am disappointed in this loss of local functionality.

I asked "why doesn't the new outlook support pst files?". It gave 5 reasons and then said "In summary, while PST files served their purpose in the past, the new Outlook prioritizes modern features, security, and cloud integration over legacy formats."

It's been half a year. Is this feature finished?