I want an email client that can download all of my existing Gmail emails and then i can search for them quickly. I have tried Thunderbird, Mailspring, Clawmail, Geary. Some of them can download all of the emails, but when it comes to time to search, they often freeze. Thus, I would then need to do the old fashion way: open up a browser and login from there.
Is Mutt ok with such requirements? Any other alternatives?
I also use GrapheneOS on my phone. Before I had Fairmail for my Gmail account but the search feature is quite buggy. So… even though i know it is shitty, I have to use the official Gmail app for my Gmail stuff. It gets the jobs done: i can search for an email 3 months ago or follow up on an old email thread very quickly.
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