Due to the high amount of notifications that the customers and partners receive we ended up having a lot of support ticket requests. Please consider sending emails only for production environments and for partner managed environments for the Sandboxes to have emails sent to the partners directly so as to avoid customer confusion and loss of trust in their partner and their reputation. Looking at this tread we can search for : Solved released 27.0  

A lot of customers partners confused and worried that their extensions are not compatible, and this leads towards frustration from their lack of understanding.