Does anyone know of a credible report that shows how many email addresses are under management by a service or being supported by an application?

https://techcrunch.com/2016/02/01/gmail-now-has-more-than-1b-monthly-active-users/ for example shows that Gmail has more than 1b (1.2 b I’ve seen elsewhere).

Don

Don Hollander

Secretary General – UASG

Skype: Don_Hollander