The Mac Email Client Sucks

That sounds like a problem but it doesn’t live up to the clickbait title: the problem isn’t even in Mail.app, which shows you which address will be used to send the reply and allows you to select a different one, or the default calendar app, which normally replies using the address an invite was sent to.

If an edge case like that is enough to brand a huge app as sucking, well, there’s not going to be much left.

I haven't really used an email client anywhere (except on my work laptop (outlook against office 365 corp email) anywhere in a long time.

I just use the web clients. I will sometimes dedicate a specific browser install just for a given platform to keep it separate, or keep separate profiles in that browser.

I really do wish that Thunderbird had good calendar and contacts integration. It was always a point of contention for me, and self-hosting was painful to say the least. In the end, it became easier to use my web browser on my desktop more often than not. I generally only use my phone's mail client(s) to reply to emails, almost never originate, and don't accept invites. I also turn reply notifications off explicitly in my mail clients.

I'd love to see either a Thunderbird remix, or something else that has nicer integrations. It's an area that's often either expensive or difficult to even get the server side working right, let alone the client. And technically speaking, as an aside, IMAP as a protocol can burn in hell.

The bug that the author describes sounds pretty bad.

However, it reminds me of one feature of Mail.app that I do like (though I'm sure other email clients have similar features): the "Mark addresses not ending with <domain of your choice>" setting.

It makes it easy to avoid accidentally sending sensitive emails to people outside of your company, since the addresses will appear in red when composing a message.