Apple Mail vs Thunderbird vs ICloud Mail

I'm sick of Apple's bugs that have been happening all over the places for years without being dealt and fixed.

I tried to like its Mail app, but unfortunately it's very buggy.

Here is the list of the most irritating issues:

1. Search functionality often doesn't work, so you can't find an email in Mail app, even in spite of it being present and can be found via web interface of the email service provider. You can read lots of similar issues on Reddit.
2. Delete functionality also doesn't work frequently, and deleted emails get restored after being deleted. You can also read lots about this issue in the Internet.

So I vote for Thunderbird.

If your email service supports the IMAP protocol, then your messages should be available on all your devices until you choose to delete them. If it supports only the POP version, then once a message is downloaded it becomes  a local message.

Apple Mail is a Mac application. It is not a web-based app. iOS devices also run the Mail app. There is no Windows version.

iCloud Mail is a service - offered to Apple customers. It can be accessed from most all mail applications on Mac and PC. On a Mac, the default choice is the Mail app - but one can use other programs as well. iCloud Mail can also be accessed via its own website. The iCloud service also includes calendars, notes, reminders and so forth. Mac computers (and iOS devices) include dedicated apps for these functions. On a PC, it may be feasible to sync this data with other apps, but the best choice may be the iCloud website.