Microsoft no longer supports something called delta sync which windows live mail uses
If you are ONLY using windows live mail (any version) for email and not calendar & contacts you can configure it to work using IMAP/POP. If you do need to sync calendar & contacts ..
There is a great replacement for Windows live mail that is free to try (up to 2 accounts) that DOES work with the new outlook mail format called emclient. There is also a paid version. You can get either here
http://www.emclient.com/
It works with Exchange, POP, IMAP, and looks similar to Windows live mail. Frankly it is the first replacement I have seen that actually works. I have switched.
They have their own support forums, a decent product, and seem to be the only replacement for WLM that has the look and feel of it.
You can import all your windows live mail into emclient easily by doing a file>import>windows live mail. This will import your current WLM data into emclient
Out of an abundance of caution I would make a copy of the entire WLM folder and save it to a safe location.
There is a good wiki on this issue here
http://answers.microsoft.com/en-us/windowslive/wiki/livemail-email/windows-live-mail-and-outlook-mail/6edb5ba6-f9f2-40fd-80a1-fc23cc6fbfe0
Wanikiya and Dyami--Team Zigzag Windows IT-PRO (MS-MVP)