I'm a bit puzzled - I have literally gigabytes of emails downloaded to thunderbird and I don't get any freezes on searching - there's 15 years of emails from my personal domain, plus 2008-2012 of active use and then passive amounts since on gmail, PLUS 3 work domains over several years in that set and I've never had it freeze.

My machine is adequate but not top end (32GbRam, Ryzen 7 3700X, 2Tb NVME/M2 SSD) - it was "good" 4 years ago when I assembled it, it's probably bottom tier by now. Running Arch, but also dual boot Mint - both are fine with it.

Just checked -there's 10.3Gb in the personal domain alone. Have a look at your PC config - unless you have tiny amounts of RAM or are running on a super slow HDD there's something wrong with this picture

Never had performance issues with searching on Thunderbird. How many bajillion mails are we takling? Have you tried a TUI mail client like aerc?

The ones from Gnome & KDE, Claws, Thunderbird. If you come from Gmail and want a GUI that is.

Btw, why do those clients need a Gmail compatibility mode, what does gmail do different?

Your performance issues are likely not an issue with thunderbird but with your hardware or some weird filesystem. Like others in the replies I have ten years of emails stored in my thunderbird inbox and they search near instantly.

It does not matter where the mails come from (gmail or other), if you are using thunderbird or any other client to store them locally, virtually all providers have an imap and pop3 endpoint the client connects to download everything

Best email client is arcane chat. Get an email that works with it. Forward your gmails to it if you must keep their service for some time.

A four part series on how to download all your emails using Thunderbird https://firewallsdontstopdragons.com/withdraw-your-data-email/

Really never had any problems with that. The only mail app I know that made problems indexing mails or keeping the index intact was Microslop Outlook for Mac. Anyways, lean back and search for the fault outside of the software scope. I guess you have either hardware issues or system configuration issues. With any mail app it should also be possible to reindex all mails. If your app stores mails as files you can also just grep the Mail folder and crossreference the E-mail's unique ID and then access it through your app. Also fairmail's search feature always worked flawlessly for me.

You could try Betterbird.

Do you mean full text message body search or just headers (To/From/Subject etc.)? Claws Mail is very fast when searching in headers, but not in message bodies.

This but a Docker or Podman pod where you can have it download your emails and allow you to send emails but thru the web so you can see your emails at work or on your phone.

emails

Not a noun, my dude.

I use seamonkey, but only for convenience. It grabs all my email and caches it locally for me.

Evolution works with the Linux kernel mailing list that can be several thousand emails a day. Just be sure to add your Gmail accounts via the gnome control panel (if your desktop is on Fedora or similar) rather than via Evolution. Also look at using AI if you have a LLM / agent with access to your inbox. Google offer this via their Gemini Pro subscription - free for a year of you happen to own a Pixel 10 Pro. I'm guessing that as you use GrapheneOS you probably don't want to give Google access to your phone. Searching via the Gmail web interface should work fine though.