Situation:
I have a couple of laptops that I use. I want to have a single configuration of several apps that I can use identically on each system. This includes firefox, mail client and my text editor of choice.
The issue with the mail client is I have a lot of historic email. I don't want to drag it all around on a key (security for one thing), but I do want to drag around the config of my mail client between the laptops.
I would like to use Portable Thunderbird, but only IF I can set it to store my mail on the NAS at home. Yes, that ties me to only using the mail client when on my network, but, that's not a problem. When away from home I use webmail now anyway.