"Outlook has six per cent"
That's six percent too many.
OTOH, I'm not exactly moving with the times myself either. I begrudge using Thunderbird because it feels overengineered and bloated, but it's my "lazy" option. I prefer Claws, which TBH is just as easy to set up. I've been known to use Emacs Gnus on more than one occasion. I'm probably most comfortable with Mutt.
If the market share for Windows Mail (or whatever name Microsoft has given it this week) is a small fraction of 1%, I dread to think how Thunderbird is faring, and for me that's the "mainstream" option. I'd like to take this opportunity to say "Hi" to the other three people using Mutt.
Of course, I'm doing it all wrong. What I'm supposed to do is use a web browser as an email client, for the ultimate bloat and lack of configurability.
No wait, that's not it. What I'm actually supposed to do is chuck my dinosaur PC into a landfill and use a smartphone running GMail, or something.
Nope, still wrong. Email in 2018 is like using VHS instead of Netflix. What I'm really supposed to do is use FB Messenger, WhatsApp and SnapChat. I have no idea what they are, but they sound utter shit. And, lets face it, in the time it took me to write that sentence those apps are already passé, and all the kiddies have long since moved on to some other pointless fad.
Back to Mutt, then.