Email Overload: Alternative strategies for distributed organizations

Randy Dean has training in this area:

https://www.proformative.com/courses/email-overload-solutions

I'm specifically wondering if others have alternative approaches that are "sticky" especially in distributed organizations for handling: -Email overload, and the impact on productivity, or; -Mis-use (imho) of email as a virtual DMS, or; -Lost governance/control due to reliance on email. Background: I've got several companies and client companies which are heavily distributed. We use Skype, Facebook, Viber, VeeSee, Line, Hipchat...etc to move data off of email. We have had very limited success in getting traction in alternatives that are more focused and more "sticky", as in tracking discussions and threads. In one instance, we used Oracle to build process specific task and thread management. It works really well, but is expensive and clunky and not at all flexible (but certainly solves the governance problem). The issue becomes more virulent, in my experience, with volunteer companies (non-profit) and with clients who don't see the value in learning a new process. War stories, case studies, and cool new apps are warmly welcomed! Cheers, Keith