Decent amount of storage, basic e-mail functionality, intuitive to use and fully compatible with mostly every device either by webpage or standalone app.
Full integration with Microsoft's Windows and office software. It has been around longer than mostly everyone of the known alternatives.
Archaic, slow to catch up, had it not been because I've been using it since 1997 and have a gazillion contacts and old emails I would have abandoned a decade ago at least.
Smaller available storage when compared to similar options.
Insecure, my account has been hacked twice since I created the email (managed to recover it both times)
Always playing catch up in features but never up to par, the UI while better than it used, still leaves a lot to be desired.
Forced integration with other Microsoft apps like Skype which somehow ends up signing online without asking me everytime I open the hotmail email.
Atrocious spam filter that lets everything through and sometimes blocks needed email.