If you don't know anything about HEY, you should check out the features tour. It is a great overview that highlights many of their unique features. https://hey.com/features/the-screener
Keyboard shortcuts are awesome. I'm surprised they don't mention it in the features tour, maybe it's only appealing to geeks like me. But you can do almost everything with keyboard shortcuts that are easy to use and memorable.
Email signatures? https://twitter.com/dhh/status/1276311062057369600
Custom domains for individuals? https://twitter.com/jasonfried/status/1273725369489727490
IMAP is probably the only qualm I have about it so far. I understand it doesn't make sense for the HEY client, but it'd be nice to manage my email from other clients. And that's not going to happen. https://twitter.com/dhh/status/1272599759686000640
Still, if there is a company I can trust with vendor lock-in, that's Basecamp. And I don't say this lightly. If worse comes to worse, their policies on what happens after cancelling the account are good. https://twitter.com/dhh/status/1275503946962857984
Being email such a critical service and Basecamp a relatively small company, you may wonder how reliable it is. I cannot say that the application was unresponsive or slow at any point. And it's not that they don't have traffic. https://twitter.com/dhh/status/1275511173782204416
@noeldemartin I've definitely had to get to grips with more shortcuts now I use i3...
HEY also shipped with a Linux client from day one, and that's what I've been using. There is a client for each platform. https://hey.com/apps