There is obviously a little bit of exaggeration but when I open my email at the workplace the bulk of the mails are:
- semi automated reminders (you haven't filled your timesheets!), usually sent by humans but that do not expect answers
- internal newsletters
- general HR news
- special news: electrical issues at the office, stay at home!
- spam
Bottom line: none is addressed to you as a particular human, nor require answers.
I am sure it changes for people who have interactions with people outside of the company but I would hate having their job and don't understand why companies haven't adopted XMPP widely to make those kind of interactions. I can theorically receive spam via XMPP, but it requires at the very least that I approve the relationship before hand so if it comes from a domain I don't expect I have no reason to accept that trust.
But on personal side, I haven't received anything from a human for years. People I know usually know my phone number and contact me via instant messaging.