Thanks it's great but Rated 5 out of 5 stars

I'm using just one email account in many persons with different pc but I don't have a server or a disk on line .... Your Idea is the best but How can I use it on all pc with my colleghe of work?
Why the notes aren't send with email?
Thanks I hope to improve my and Thunderbird works with your add-on Thanks

This review is for a previous version of the add-on (2.2.6). 

Dropbox as potential solution

Just read a comment of someone who uses Dropbox to synchronize the notes. This most probably requires to manually specify the storage path in the XNote options.