We always liked email router, we even called it “good, old, and fairly reliable“, and asked people not to leave it behind. But, as the server-side synchronization becomes better and better with every release, it’s time to reconsider.
According to the list of the upcoming important changes, “Email Router will become deprecated in the next major release of Microsoft Dynamics 365”. Next major means the imminent 9.0 release. Come the major release after, email router will be officially “not a thing” anymore. In fact, even if you try the version of the router from the previous build, it will be pretty much bricked due to the fact that it relies on SOAP and the version-after-next will have SOAP support removed.
You still have time but I recommend booking that restaurant for the farewell party and starting money collection for the gift.