You can send mails directly from Method but currently there is no way to directly receive e-mails in Method. There is the Outlook add-on that allows you to send e-mail to Method, however, this wouldn't help us achieve what you are looking for. To enable Method to create a new case when an e-mail is received would mean that Method would have to receive e-mails directly.
If you wanted to create cases when e-mails are sent from Method, then most likely that would be possible via customization.
Hope this answers your question, let me know.