We're not sure how you managed to send us those messages, but you did -- a lot of you. Seems Outlook has been experiencing all sorts of issues. Microsoft's privy to that fact, and we assume looking into it as we speak, noting on its status page, "We're having a problem accessing email. You might not be able to see all your email messages." Looks like Hotmail, Messenger and SkyDrive are having some issues right now, as well. We're reaching out to Redmond to find out exactly what's up.
[Thanks to everyone who sent this in]
Update: Microsoft got back to us to say it is aware of the issue and looking into it. It claims that, whatever the problem is, it's only affecting a small number of Outlook and SkyDrive users. You can check the Live status page here for the most recent updates.
Update 2: Looks like MS has been able to restore access for most users, though some are still having issues. Here's a followup statement from the company, "Outlook.com experienced an incident that caused some users not to be able to access their account or share their SkyDrive files. We have restored web access for all users but some people might still see issues with their mobile devices. We are working to restore full mobile access as quickly as possible."