Recommend mail clients for Linux?

Question

gmail

Is there a normal mail application for Linux? And it is desirable that it would work under a proxy)
PS: do not offer thunderbird and Evolution.
Here's what I mean by "normal application":
1) Thoughtful design. In order not to look for buttons where there are none.
2) Minimum settings. I don't like to go to Google for half a day to set up a product, this is where the company's proxy belongs.
3) Necessary set of functionality. For example, connect two mails quickly, drag a picture and not look for it in folders.
4) Good performance characteristics. Fulltext for all spam.
5) That the synchronization would be good. I'm not satisfied with checking mail every n minutes. Many popular providers have callbacks for receiving emails.
6) Ability to add any labels and filter by them.
7) Preview of links (so as not to drag them into the browser) and other attachments.
8) Correspondence threads (with many people on the same topic), like in gmail, for example.
9) And a mega topic would be sending large files (via some kind of cloud).

Answer 1

And I like Thunderbird.
Take your pick:
alternativeto.net/software/mozilla-thunderbird/?pl...

Answer 2

Kmail

Answer 3

I'm for Thunderbird, but try also
sylpheed.sraoss.jp/en

Answer 4

What does "normal" mean in your opinion?
Most of it is there anyway in Thunderbird. And in fact, the problem is that the choice will not be very large :) TB, Evolution, KMail, Zimbra mail client (incredible asylum). At one time I was a direct fan of KMail. True, he has serious problems receiving mail from MS Exchange via IMAP and with certificates - I actually never got to know how KDE works with certificates. Now I use TB - not because it's the best, but simply because it's the only cross-platform client.
Can it be easier to say what does not suit you in TB - what if it can be solved?