Thunderbird can no longer retrieve my mail from Hotmail. It worked a few days ago, and then I got automatically upgraded to Windows Live and now it doesn’t. I suspect the two events are related.
Anyone know why?
Hotmail does not provide internet standard IMAP/POP access to mailboxes - it is web only (to make you look at the ads). You must be using a webscraper extension - which reads the web pages and parses the info out of Hotmail into Thunderbird (I use a similar tool for my email server). These webscrapers are sensitive to the page layout. A small change at the MS end can break the tool. And MS seem to be making a lot of changes at present.
So the tools are broken until they are updated for Live. 
You need a new Live Mail extension.
Si
I get my messages from one of three Hotmail accounts; the other two asks for password, and then tells me: “Negative vibes from [Hotmail address].” It has always been this way. I googled a lot, but still don’t know why. It’s a pity.
I’ve found improved performance by switching the Hotmail plugin to WebDAV mode.