[Mailman-Users] yet another message filtering question

[Grant Taylor]

On 12/31/08 11:34, Mark Sapiro wrote:
> You can filter based on file name extension, but that filter only 
> affects MIME parts that have a filename or name parameter in the 
> Content-Disposition: header or a name parameter in the Content-Type: 
> header. Many MIME parts will not have a name/filename so they can't 
> be filtered based on extension.

I don't know of any email client that will send an attached file with 
out the "name" parameter to the Content-Type: header.  So, with this in 
mind, it should be possible to deduce that any MIME section that is not 
text/plain or text/html (or their multipart/alternative encapsulation) 
that does not have a "name" parameter is very likely embedded content 
and as such probably ok to remove.

> The concept of attachment is not well defined in MIME. There is a 
> Content-Disposition: header that can specify inline or attachment, 
> but Mailman doesn't look at it.

I think the word "attachment" needs to be better defined here.  Are you 
referring to what an email author ""attaches to a message, or any thing 
else that is embed with in the message.  I think the actual attachment 
(by the message author) will always have a Content-Disposition of 
attachment.  It should only be embedded content that differs.  Though, I 
know that some MUAs will embed pictures rather than attaching them.



Grant. . . .