After some help from you all as so far have been unable to find whats causing this/how to disable.
Created a Work Progress Tracker list on a private Sharepoint, with start and end dates etc. However when upcoming end date is approaching, an email is sent out to users (weirdly from an unrelated email address).
I would like to disable this.
From what i can see no alerts are enabled across the sharepoint site, and no manual intervention has been done.