If I want to switch an email account from pop3 to IMAP do I have to delete it and re-create it again ?
Yes, that is the only possible solution at the moment.
Maybe one should just add that POP3 does NOT retain mails on the server so if you are changing from POP to IMAP you may find that some of your older mails are no longer there.
It might be wise to export the sent and received items before deleting and then importing them once the new account has been created?
Kind regards,
Tony Robson.