What's the correct way to deal with a linked folder

[Hilary]

I came across this when trying to use UR to handle a folder-full of emails created with Windows Mail, but I imagine it'd be the same basic issue whatever was in the folder.

I go to the folder in Explorer, right-click and choose "Send to Ultra recall (link)". Now I can add keywords, due dates and reminders to these files, which would be hugely useful for emails.

But then - outside UR - I delete some of the files. They don't disappear from UR; they're still there, but clicking on them gives 'access violation' errors. I think 'maybe it refreshes the listing when it loads the database,' and close UR. Next day, seeing all the non-existent files still listed, I remember ctrl+F5. This says it's synchronising the folder, but in the end it only gives me another error message (sorry I didn't make a note of it, something about RTT, or was that RTTT?).

I gave up and deleted the folder. But surely this isn't what's meant to happen, and something's gone wrong here? It must be possible to link to a folder in UR, and still remove files from it outside UR?

It occurs to me this might be a particular problem to do with how Windows Mail creates and manages its email folders. If that's the case, can someone tell me how UR integrates with Thunderbird, and what's possible there?