1464490 - I would like Securemail to include an unencrypted message in a MIME part

Status: NEW

(bugzilla.mozilla.org :: Email Notifications, enhancement)

Description

[:Atoll]

Hi, please consider extending Securemail to extend the MIME structure to include an unencrypted message to the recipient.

Right now, we send messages using the following MIME structure:

    multipart/encrypted
    .. application/pgp-encrypted
    .. application/octet-stream

I believe that we should additionally include an unencrypted part with a basic explanation that uses the normal BMO plain and/or html template to convey a link to the bug in question and a link to userprefs, as well as some phrasing about "This message contains an encrypted attachment with more details".

I propose that we trial using either multipart/mixed or multipart/alternative to provide additional unencrypted content for mail clients that cannot interpret multipart/encrypted content (such as Gmail, which is widely used by Mozilla staff).

If we were to pursue multipart/alternative, I would model the proposed structure after BMO's existing HTML emails. This example assumes HTML email is enabled in the preferences, but if not, simply deleting the text/html part would suffice.

    multipart/alternative
    .. text/plain
    .. text/html
    .. multipart/encrypted
       .. application/pgp-encrypted
       .. application/octet-stream

If we were to pursue multipart/mixed, with HTML email enabled:

    multipart/mixed
    .. multipart/alternative
       .. text/plain
       .. text/html
    .. multipart/encrypted
       .. application/pgp-encrypted
       .. application/octet-stream

Without HTML email enabled:

    multipart/mixed
    .. text/plain
    .. multipart/encrypted
       .. application/pgp-encrypted
       .. application/octet-stream

Assuming that *any* of these methods works when tested against clients capable of decrypting Securemail, I feel that implementing them would vastly improve the Securemail experience for users where only a fraction of their devices understand multipart/encrypted.