USB encrypted email for both windows & linux?

Hey all, my first post here!

what i'm looking for is a way to have USBstick-portable encrypted email, and be able to use it on both windows and linux PCs.
I've been using TBP+Enigmail before, and it's as good as ideal - except for that i can't read or send encrypted emails if i only have access to a linux computer at the moment.
This is some serious impediment to my "portability".

So, is there any fairly easy/working solution available? (my coding/geekery skills are absolutely minimal btw, so that kind of advice is not very useful to me. but if it's good, post it anyway )
What about Wine? i get the picture Thunderbird doesn't work that well with it, so i suppose encryption would make matters ten times worse...
I imagine there could also be a solution involving having the USB & programs in linux, and some form of adaptation for windows PCs, instead of the other way around. Please tell if u know about something like this!

I know similar questions have been discussed before here, but none of it seemed to fit my specific needs and skills. Also, although i do have some basic, basic grasp of how all this stuff works, my knoledge is totally not comprehensive & all-covering, so please put up with me possibly not knowing something very basic that "should be common knowledge" (and/or using terms wrong). That means that there could also be some very simple solution that i just don't know of b/c of not having done my homework.

(Someone somewhere said that Thunderbird by itself is compatible with both Windos & Linux - but you still have to format yr specific program to one OS or another even when u have it on a USB stick, no?)

thanks in advance,
twatter