On Mon, Apr 16 2012, Mark Walters <markwalters1009@gmail.com> wrote:
> On Mon, 16 Apr 2012, David Belohrad <david@belohrad.ch> wrote:
>> I receive an email with attachment. It says it is a pdf, e.g. like this:
>>
>>  [ Ultra_Low_Noise_AC_Beam_Transformer2.pdf: application/pdf ]
>>
>> when I click on it, I would assume, that it opens the file using
>> 'default' application, which is - when looking into file associations -
>> okular.
...
> it is customizable under M-x customize-group notmuch -> notmuch-show ->
> Notmuch Show Part Button Default Action:
>
> The "view" option  uses the mailcap entry to open the attachment.

Also, when the cursor is on the button you can hit 'o' to open with
default mailcap app, 's' to save, and 'v' to view with a specified app.

jamie.