Search function stopped working entirely across Mac Mail and Finder

I am on Sequoia v15.5 (don't have Ventura installed anywhere) and I can search and find content in any of my three Apple Mail inboxes, or Mail sub-folders. Just realize that the Spotlight keywords (if used) may be different in Mail than in the Finder.

Let's say I received a new license key from Sublime HQ Pty for my Sublime Text 4 (4200) update. I can search in Mail by in the following ways, all receiving one or more hits. Clicking on those hits reveals which Mail folder it is in:

🔍 From: HQ
🔍 sublime
🔍 HQ AND Subject:license

I'd run these in Onyx...

I’d get Onyx.app for Ventura, run the maintenance procedures, which includes rebuilding the lsd & Spotlight DBs & clearing the caches… it’ll take a few hours to correct things.

Try rebuilding the Spotlight index according to this Apple document: How to rebuild the Spotlight index on your Mac - Apple Support.

Onyx I not in the App Store but completely safe on the developers site, get the version for you OS…

https://www.titanium-software.fr/en/onyx.html

I understand CMM has improved but I cannot recommend it.

There is no comparison.

OnyX is now much less needed (and in fact I have not installed it in my macs for years), but is a respectable application that clearly tell users what is doing. It has been supported by its developer by some two decades, and always free.

CMM is often referred to here by its nickname "brickmymac". It preys on users fears, peddling the false idea that your mac needs "cleaning", when it has been known to "clean all too well", deleting files that should be left alone. In old days, one often needed a complete system reinstall to restore functionality. In recent years, its capacity to inflict damage has been greatly diminished, but that is because the OS is mounted on a sealed volume that cmm cannot tamper with...

Good to hear my friend, I recently had Spotlight refuse to index drives in Mojave, Ventura, & Sequoia, despite even the terminal methods using sudo, but using Onyx to reset Spotlight, the Launch DB, and clean all the system caches worked much to my relief.

You can try selecting all of the mailboxes in the side bar and selecting the Mailboxes ➙ Rebuilt menu option. Let it run for 10-15 minutes.