User blog comment:DaNASCAT/Technical Update: August 22, 2016/@comment-1038387-20160823173824/@comment-5275700-20160823192104

A Discussions-specific email preference will be in Thursday's release. The emails should not be sent if you've disabled all emails from Wikia. I checked and that does not seem to be the case for you Tupka, at least at the moment.

The emails come when a post hits 5, 25 and 100 upvotes. This aligns with the push notification thresholds.