On Tue, 03 Sep 2013 10:56:36 +0900, "Stephen J. Turnbull" email@example.com wrote:
R. David Murray writes:
I can understand the structure Glen found in Applemail: a series of text/plain parts interspersed with image/jpg, with all parts after the first being marked 'Contentent-Disposition: inline'. Any MUA that can display text and images *ought* to handle that correctly and produce the expected result. But that isn't what your structure above would produce. If you did:
multipart/related multipart/alternative text/html text/plain image/png text/plain image/png text/plain
and only referred to the png parts in the text/html part and marked all the parts as 'inline' (even though that is irrelevant in the text/html related case), an MUA that *knew* about this technique *could* display it "correctly", but an MUA that is just following the standards most likely won't.
OK, I see that now. It requires non-MIME information about the treatment of the root entity by the implementation. On the other hand, it shouldn't *hurt*. RFC 2387 explicitly specifies that at least some parts of a contained multipart/related part should be able to refer to entities related via the containing multipart/related. Since it does not mention *any* restrictions on contained root entities, I take it that it implicitly specifies that any contained multipart may make such references. But I suspect it's not implemented by most MUAs. I'll have to test.
OK, I see what you are driving at now. Whether or not it works is dependent on whether or not typical MUAs handle a multipart/related with a text/plain root part by treating it as if it were a multipart/mixed with inline or attachment sub-parts. So yes, whether or not we should support and/or document this technique very much depends on whether or not typical MUAs do so. I will, needless to say, be very interested in the results of your research :)