Creates and returns a Mime object containing the contents of the email. This method is provided for those users that need full access to every aspect of the MIME message, such as manipulation of the message headers of attachments and related items contained within message subparts. (The returned Mime object returned is locked, and needs to be unlocked with a Chilkat S/MIME .NET unlock code, which can be obtained by purchasing a Chilkat S/MIME .NET license.)