So it's working and I'm collecting analytics data using Clicky - but because the webmail is a SPA using Angular the only "page" people are visiting is /interface/root; which makes sense. I can still get information about the end-user's environment though, which is still quite useful (OS / device / browser / etc).
However, I think it might make sense for SmarterTools to integrate an analytics option a little more fully. The only configurable thing that should be required for the mail server administrator would be the "site id" of the GA account that is setup. If entered, then SmarterMail takes all the steps needed to incorporate GA throughout the webmail including routing. I found this library after a quick search:
http://angulartics.github.io/
That library makes it easy to plug in whatever analytics provider you want, however, in terms of complexity for SmarterTools I'd suggest just making it work with Google Analytics for now.
Thanks for the consideration.