Windows – Sync Windows Live Mail between two computers

I have a laptop where I have been using Windows Live Mail as my email application for the last year. Yesterday I got a dell desktop as well and I am desperately trying to set up so my desktop and laptop sync the email between each other.

I'm using Super Flexible Synchronizer to sync the email storage folder to a NAS on my network, so when setting up the desktop naturally I set it up to download all from the NAS. But each time I open Windows Live Mail on the new machine, some emails suddenly come in duplicates, one is read, the other is not.

I have ran through the registry on the new machine and updated an ID i found, in 3 places, one being:
C:\Users\\AppData\Local\Microsoft\Windows Live Contacts{blah blah blah}\DBStore\contacts.edb

Still doesn't seem to be enough. Does anyone have any tips or ideas how to sync Windows Live Mail between two computers without duplicates and weird behavior etc.