There's a big distance between "works for me" and "delights me."
I use Thunderbird on Linux and Windows. It "works for me," in the sense that it's stable and predictable and doesn't lose my data. But it also has lots of niggly little problems that annoy me, like UI decisions that made more sense ten years ago than they do today and limited tools to support people like me who have a ton of mail.
So while I use and recommend Thunderbird, I also would love to see something come along that is so much better that it makes me fall in love with it, instead of just shrugging my shoulders and resigning myself to this being as good as things get.
How much are you looking to pay for this? How many people are looking for delight in their email client? Do these numbers multiplied add up to a few tens of millions?
I use Thunderbird on Linux and Windows. It "works for me," in the sense that it's stable and predictable and doesn't lose my data. But it also has lots of niggly little problems that annoy me, like UI decisions that made more sense ten years ago than they do today and limited tools to support people like me who have a ton of mail.
So while I use and recommend Thunderbird, I also would love to see something come along that is so much better that it makes me fall in love with it, instead of just shrugging my shoulders and resigning myself to this being as good as things get.