Ask HN: If you could reimagine your email inbox, what would you pick?

I can think of things like

1. built-in mail merge and updatable contacts where someone can directly reply to your mail-merged email and unsubscribe

2. shareable urls of emails - I hate that I can only forward/cc people to share an email with people. Shareable emails will make bookmarking important emails in the browser MUCH easier

3. sidebar comments/discussions section built into the email inbox instead of unending chains of reply/reply-alls.

Anything else that could make the email inbox more interesting?