Ever decade or so somebody tries to re-invent or fix the notion of email - recently we had HEY from 37 signals but they wanted to charge $$$ so it never gained

Ever decade or so somebody tries to re-invent or fix the notion of email - recently we had HEY from 37 signals but they wanted to charge $$$ so it never gained much traction. Nobody has really solved the email threading problem - Outlook/Exchange tried but never got it right and Gmail never bothered but gave you very fast search ability on all emails you received in your account which is good enough. MS Teams - don't go there - it is slow - terrible and confusing and only succeeded because of Covid and that it was free and made by Microsoft