With the advent of DKIM and DMARC email is becoming an increasingly complex thing for small businesses that often rely on 3rd party systems and mailing lists. Personally I think email has had its day and there are far more effective forms of communication.
A good old fashioned phone call is still the best method of resolving disputes and complications IMO. To many issues are compounded with hasty texts and tweets that can’t be retracted or the tone or context understood.