So we do have communication with Plesk on this. As stated, the old API is still enforced, so there shouldn't be much needed on the part of Plesk to get they're 17.x to work with our "17.x". There is an issue in their testing where they stop mailservice.exe and try spinning up a different mail server...but I'm not entirely sure why that's preventing them from moving forward.
So, I've asked them for some clarification. I don't see that being an issue for the majority of customers who use SmarterMail and Plesk, so I've asked them to give me some additional info on how/why that's delaying their compatibility testing.
Derek Curtis
COO
SmarterTools Inc.
www.smartertools.com