[imapext] General Request for Assignment (imap-keywords) (was: [JMAP] SMIME Attachments)

[vaibhav singh <[e-mail]>]

Hello,

In order to optimize the way attachments inside encrypted mail are treated
by the MUA, I am suggesting the registration of a "$HasEncryptedAttachment"
to the IMAP Keywords registry[RFC5788].

Please find details of the original proposal below:

> Type of Assignment:
>  Requesting for addition of a keyword "$HasEncryptedAttachment" to the
> IMAP Keywords registry[RFC5788].
>
> Registry:
> The registration request is being made for IMAP Keywords
> registry[RFC5788].
>
> Description:
>     This flag can be useful so that the MUA can display an attachment
> icon when displaying
>    messages in the folder, without it having to decrypt the message.
> This flag can also be used to filter
>    encrypted emails with attachments.
>
> Additional Info:
>  The $HasEncryptedAttachment IMAP keyword will be used by IMAP/JMAP
> MUA to
>    specify that the marked encrypted message contains an attachment.
> A MUA-with-keys
>    sets this keyword when it sees a message having an attachment
> before encryption.
>     This flag can be useful so that the MUA can display an attachment
> icon when displaying
>    messages in the folder, without it having to decrypt the message.
> This flag can also be used to filter
>    encrypted emails with attachments.
>
> Once set, any entity (be it the MDA or receiver's MUA) SHOULD not edit
> the flag.
>
> JMAP Message Stores SHOULD be able to store the
> $HasEncryptedAttachment keyword.
> They MUST preserve it on the COPY operation.  The servers MUST
> support the SEARCH KEYWORD $HasEncryptedAttachment.

Please find comments by Mr. Barry Leiba, and my answers below (marked as
<vs>):

1.) There should also be a “has no attachment” keyword, so the MUA doesn’t
have to check either way and only needs to check if neither is set.

 <vs>  Agreed. </vs>

2.) The keyword is poorly named: it’s not about an encrypted attachment,
but about any attachment.  I suppose that in the end there no reason to
mention encryption at all, because it could be used for any message, though
it’s less important for unencrypted ones.

 <vs> Not really sure. </vs>

3.) How will the server know to set the keyword?  The server also can’t
decrypt an incoming message, and so it can’t check.  Where does the
knowledge come from?  It seems that it could only work for messages that
are created locally, with the keyword set at creation.

  <vs> A better use case for the flag could be: the server could set this
flag to true when it sees the mime being decrypted the first time, so that
any scans later on would not have to decrypt the mail again to know the
presence of the attachment inside it </vs>

Will this be useful?

-- 

Regards,
Vaibhav Singh