as far as I know, the name parameter is only defined for the
application/octet-stream content-type. content-disposition is the
standard way to associate a filename with a MIME body part.
many user agents have supplied a name parameter with other
content-types, but this is not standard and never has been.
content-disposition was defined some time after the original MIME
specifications that defined the name parameter for
application/octet-stream, so many user agents borrowed the name
parameter for use with other content-types.
RFC 3851 appears to be recommending nonstandard behavior, though it is
probably mostly harmless.
Francesco Gennai wrote:
Question about composing a MIME part where I would suggest
also the file name.
In the case that I would suggest a file name to the remote
MIME client could I use only the name parameter of the content-type
or MUST I add the content-disposition header with the filename parameter?
My doubt come also from the following sentence in RFC3851
(Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.1
.. ..... .
3.2.1. The name and filename Parameters
For the application/pkcs7-mime, sending agents SHOULD emit the
optional "name" parameter to the Content-Type field for compatibility
with older systems. Sending agents SHOULD also emit the optional
Content-Disposition field [CONTDISP] with the "filename" parameter.
If a sending agent emits the above parameters, the value of the
parameters SHOULD be a file name with the appropriate extension:
.... ..... ...
where a system using only the name parameter is considered an "old system".
So, I don't understand if "old system" is related to some old S/MIME
system, or to a generic old MIME system....