On one system I tried, the update appeared to prevent emails from being sent or received, but after a reboot it did work again, albeit slowly. I am good for now, but this is just a temporary fix, unless MS fixes the patch before the changes are made. I uninstalled WLM 2012 and then reinstalled (the reinstalled version does not have the patch). It was crashing when 'updating calendar' upon launch. I can't change the pane layout at all, just apply stupid colours and pictures to the background that frankly I don't need to read my mail. The new mail program in W10 doesn't appear to meet my needs. I either have to go through the hassle of uninstalling it and trying again in the hope it doesn't kill it or switch to outlook which I really don't like. I can no longer access any of my email accounts from any provider as the client simply says it has stopped working and closes. I just installed this update because I like Live Mail 2012 and its totally killed it.

I had the same problem as you, but I found that if I uninstalled Live Mail and re install it works again ,just dont run the patch.All your mail should still be there.