Microsoft currently has the IP for my webserver blacklisted for e-mails. I've already started a process to see if I can get this lifted, but it will be a waiting game and it may not happen. Whoever had this IP before me must have been a bad cookie.

I did fix a few other e-mail issues that some may have been noticing... or not noticing from the lack of emails being sent out. Yahoo and Gmail are now working for me. I've yet to get any more bouncebacks from anyone other than microsoft now, so we will see.

In short, if you use a microsoft mail account, then consider using another service for now until it gets resolved. Or else no notifications will ever reach you.