<< What can I do to make sure that my attachment opens in the right
programm(, using its mimetype). >>
You should verify whether the mimetype is actually set in the attachment
object (in the mimetype field, iirc).
There are issues with older versions of mmbase where that mimetype is
not filled in correctly (fixed, I think, in newer releases).
If the mimetype is set to application/pdf, it should download the file
as that type.
Pierre
