Migrate entire IMAP4 mail, including folders structure, to Gmail

When I am adding a new external IMAP4 server to Gmail I am offered an option to specify a label under which all mail from that server will be categorized in my Gmail account.

If I do so, will Gmail recreate entire folders structure under that label or will it put all fetched e-mails directly to that single label and I will be forced to optionally recreate folders structure manually?

I have 6610 e-mails, organized into 196 folders, to be imported to Gmail from external IMAP4 server. Will I have them imported organized or in “bulk” mode?