Virtual emails for IMAP commands

摘要

Some embodiments provide a method to extract metadata of MIME attachments or other distinguishable MIME parts of MIME emails into virtual emails. The virtual emails do not contain the full MIME attachment data but instead include some or all header fields of the parent email which contains the MIME attachment and a link to the MIME part of the MIME attachment in this email. The virtual emails may be stored in a separate namespace, or a folder which may be hidden from some IMAP clients, on an IMAP server. The virtual emails may be indexed by the IMAP server like any other email. Virtual emails may be created when new emails arrive on the IMAP server and synchronized automatically, e.g., when the parent email changes. As such, standard IMAP commands like FETCH, SEARCH, SORT, THREAD, etc. may be used for virtual emails.

主权项

1. A method to process multipart Multipurpose Internet Mail Extensions (MIME) messages, the method comprising:
receiving a multipart MIME message; determining that the multipart MIME message includes a distinguishable MIME part, including determining that the multipart MIME message includes a MIME part with CONTENT-DISPOSITION that includes “attachment”; processing the distinguishable MIME part, including generating a virtual email that represents the distinguishable MIME part; and adding the multipart MIME message and the virtual email to an electronic mailbox of a recipient of the multipart MIME message, wherein generating the virtual email includes:
copying header fields of the multipart MIME message into the virtual email;saving a subject field of the multipart MIME message as a different field in the virtual email that indicates a subject of the multipart MIME message from which the virtual email is derived;saving a filename of the distinguishable MIME part in a subject field of the virtual email; andsaving as a mail body of the virtual email a link to the distinguishable MIME part in the multipart MIME message.