[jedberg]

I think you may be right about the downfall of personal emails, but email still has a strong place in business. I still find it the best way to have a long discussion with thoughtful responses, especially if it's tied to a newsgroup system (a la Google Groups and it's email gateway). It's still far superior to Slack et al for that kind of thing.

Also, incidentally to your point, it's a lot easier to control spam within a company email system. As a broad brush, you can just set your client to automatically relegate any email from outside your organization to another folder.