I can only speak to my experience, but email is very very much a part of our world in our software company. It's WAY better than Slack or other IM/group chat tool for search and archiving later -- and, let's be honest, a WHOLE LOT of stuff gets decided in email, so that's pretty important.

With a distributed team, it's even moreso. Plus, since we're distributed, the idea of email-as-document (with rich formatting and inline images) is just that much more normal.