I've started using Thunderbird again after months of trying literally every other solution on the market. I wanted to switch from Outlook and Gmail to something that is fast, has good keyboard support and a good message editor. It's incredible how slow most of the email clients on the market are. What's even more incredible is that, apart from Outlook, none of the other clients offer a good way of editing tables prop…
It really is odd. I've tried a handful of clients, but the one I wanted to work the most was MailSpring. The UI was clean, it was supposed to be fast, and have great integration off the bat. I forget if it was my gmail, my student email (through gmail), or my hotmail account, but one of them would just refuse to connect. If I can only have 2/3 of my emails, I'm not going to bother. That was a few months ago, so maybe it's fixed, but damn.
Thunderbird works, but if they could have some easier customization, I think they could really take back some of the market.