Managing personal Outlook.com account settings, security, and privacy
Wow, In a way I am glad it's not just me who is frustrated at the obvious pointlessness of reporting spam / phishing mails. I used to get about 50 per day, so I started reporting them, they are now at about 150 a day after 3 months. Pretty much all are of the same message just from variations of the sender address. I set up rules to auto delete the most common elements in them but within 10 mins of setting the rule I had more coming through.
Effectively what I have discovered is that if you try to report them you get more - it's like adding water to a mogwai.