Migrate from thunderbird to sylpheed while preserving folder structure

Is there an automatic way migrate a thunderbird mailbox to sylpheed while preserving the folder structure. I tried the importexport extension for thunderbird and got a directory with multiple mbox files and subfolder which contain again mbox file. For example inbox1 inbox2 foo.sdb foo1inbox1 foo2inbox1 foofoo.sdb foofoo1inbox1 foofoo1inbox2 foo2.sdb foo2inbox1 foo2inbox2 Sure I can import manually every single mbox file with sylpheed, but is there an automatic way to import all at once and preserve the folder structure?