Re: [Jmap] the large email (attachment) problem

Neil Jenkins <neilj@fastmailteam.com> Mon, 02 August 2021 20:50 UTC

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Date: Tue, 03 Aug 2021 06:49:40 +1000
From: "Neil Jenkins" <neilj@fastmailteam.com>
To: "John Levine" <johnl@taugh.com>, "IETF JMAP Mailing List" <jmap@ietf.org>
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Subject: Re: [Jmap] the large email (attachment) problem
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On Tue, 3 Aug 2021, at 05:58, John Levine wrote:
> I suppose, but if the HTML fits in the message, what's the point of the external version other
> than to debug your MUA?

Sorry, I wasn't clear. The HTML version is a (prettier version) of something like this:

<h2>Attachments</h2>
<a href="https://example.com/download/large/file">whatididonmyholiday.mp4</a>

So if your client doesn't support the external body, it will instead show the sender-generated links to download the attachment (which is exactly what Google, Microsoft etc. currently do). But if it does support the external body, it can show it like any real attachment and offer the advantages we've discussed (immutability, privacy-preserving caching on delivery etc.). This provides a seamless upgrade path to offer the feature.

Neil.