According to this link, https://technet.microsoft.com/en-us/library/hh699689.aspx#Exch_svr, Exchange 2016 is not on the list of supported systems.
however, for sending emails I would have thought treating Exchange 2016 as a SMTP server should work but I have not tried this.
In any case, I recommend that you consider switching to Server Side Synchronization because the Email Router is deprecated - in a future version it will be removed.