That's an absolute address. Change IsRelative to 0 (zero).

I'd also change the profile name to something other than "default", but that's just a personal preference. You have gone out of your way to do something off-piste, so the "default" moniker isn't really appropriate. However, I digress. ;-)

You find it works well like this? My understanding is that any small change to a mailbox file would lead to that file having to be up/downloaded in its entirety, and many users' mail stores are gigabytes in size. So every change to a large file in your profile would invoke a lot of internet traffic.

It would probably be more efficient if you used maildir storage, where it uses your native file system to manage the files representing email messages, so it's lots of tiny files and these can be up/downloaded piecemeal and hence efficiently.

More thoughts:

I wouldn't use this shared profile scheme myself, because I use Windows and Linux, and the Lightning calendar, in particular, has to be binary compatible, so I can't share a profile incorporating Lightning between these platforms.

Another reason for not using it is the space limitation on Dropbox.

And another is that if you can't get online, you have nothing. A local profile will let you at least read saved messages, and access your Address Book. I frequently visit clients who offer no internet access and so I need to rely on my local and portable store of correspondence.

Hi,

Thank you for your answers, but I am confused!

I've been using Thunderbird for over a year, and whatever configuration I came up with a year ago has been working just fine with two Windows computers coordinating folders via dropbox.

(1) my mail is available even when there is no internet .. it just doesn't get backed up until I'm online.

(2) My email is stored over dozens of separate folders with thousands of small files, so I don't have bandwidth problems

(3) synchronization conflicts are handled gracefully and easily fixed.

As I recall, the trick was to tell Thunderbird to store my email on local folders on both computers -- I just don't remember what I did.

Can you figure out what I need to do so that my new installation of thunderbird can see all the old messages?

Thanks

The only thing that I've seen so far is the IsRelative. You are giving a full absolute pathname to your profile folder so IsRelative needs to be false, or zero.