Why aren't folder properties retained when a profile is moved?
I moved my T'bird profile. Afterwards, I discovered all of the retention folder properties had been lost and all folders were now using the account default setting. And, for completeness sake, the customization of the folders via an add-on (color folders 1.1) had also been lost -- the extension still functions but all folders which had been set to something other than the default color were now sporting the default color. The account is for GMAIL and is configured as IMAP.
Opaite Mbohovái (2)
Your experience differs from mine. When I move the entire profile, intact, I get exactly what you're asking for.
How did you move it?
I used to old tried and true method: allocate a new directory, copy the old profile using Windows Explore then edit the profiles.ini file as directed in the MozillaZine KB article.