Seems like we've gone a it backwards in SM16 with the "Message Traffic" report in that nothing seems to exist which had the same information in one nice report.
The closest thing in SM16 is Domain Reports -> Incoming Messages and Domain Reports -> Outgoing Messages; and then for each to choose the "Users" option instead of "Trend". However, unlike SM15, in SM16 the "Users" option only shows users, not aliases or mailing lists.
Are there plans to revive the old SM15 Message Traffic Report? A single report which shows, for all users, aliases, and mailing lists, the number of incoming and outgoing messages for a given date range?
If not, are there plans to expose this data via the new API so we can grab it on our own? Again, in particular, not just users but also aliases and mailing lists.
The reason this is important for us is because we're transitioning to email hosting plans based on "usage" - where that usage is determined by a number of things like the traditional user count and storage, but also (and even more so) by the volume of messages passing through the server which we need to process / spam check / administrate.
The logic is that since we're on SM Enterprise Unlimited the mere existence of mailboxes doesn't have a noticeable cost unless those mailboxes are actually used. Same with aliases - if there are 1:1 and used "normally" don't have a large impact but a frequently used alias with 50 people on it does. The ability for us to measure this data and help our users understand what effects their usage practices have helps to ensure optimal efficiency for everyone involved.