The key is to realize that Slack et al are really good for synchronous communication (users need to be present simultaneously to really be effective). EMail was designed for asynchronous (reply later) communication. The expectation that everything can be done synchronously is unrealistic. The reasons for this are users spread across multiple timezones, unavailability of a party, the need for some thought and consideration etc. 
Unfortunately, email, as we all know has a lot of flaws.<p>An ideal comprehensive communication infrastructure would be one that encompasses both synchronous (Slack, Hipchat etc.) and asynchronous modes but in such a way that one doesn&#x27;t create two disjoint islands as is the case now between chat and email.<p>TMail21 (<a href="https:&#x2F;&#x2F;tmail21.com" rel="nofollow">https:&#x2F;&#x2F;tmail21.com</a>) is an asynchronous communications platform that is designed (amongst other things) to integrate with chat apps so the appropriate communication mode can be used at the appropriate time.<p>At the end of the day there is no silver bullet to the team communication and collaboration challenge. There are so many permutations and combinations of use cases. It&#x27;s a matter of picking the right tool for the right job.