It turns out that the recently posted Service Pack 1 on the 
Windows Update web site will cause Outlook and Outlook Express 
to think that PDF attachments are unsafe. By default such 
attachments can not be viewed or saved. Justifably, if surprisingly, 
Office files get the same treatment, so this is not merely sign that 
MS is plannng a competing product.

However, it is possible to remove .PDF from the list of 
unsafe extensions.

Go to:

Start|Settings|Control Panel|Folder Options|File Types|PDF|Advanced

and deselect the "Confirm open after download" box. In spite of 
the box label, which describes the effect of this option in 
Explorer, the effect in Outlook is to allow PDF attachments to 
be viewed and saved.

I prefer this to the instructions elsewhere for turning off 
this safety feature entirely. That is the advice given on the 
MS website, but it suggests that MS consider this only a 
"checklist feature" implementation of "secure by default" that 
they don't expect to be left in place.

Now if I can only figure out how to get .FOR off the unsafe list.

Daniel Feenberg
feenberg at nber dotte org