I downloaded Thunderbird on my Mac and am doing the accounts settings through IMAP. I am trying to synchronize all my emails from different email accounts to local folders and sub-folders. But I am facing a few problems with this: 1- Some sub-folders have been synced with duplicate and triplicate of the same emails. 2 - Some sub-folders have not been synced and therefore do not contain any email. 3 - In the gmail accounts I checked the folders to have them synchronized as specified in the help for it but it looks like it did nothing. 4 - Is it possible to synchronize only selected emails by date and not all 80 000 emails?

Thank you!