You can do this by going to Explorer and editing the default Open behavior for . File associations are added by the system administrator, and again enforced globally or for specific Exchange groups. The Other attachment group is a fall-through that contains all attachments not included in Level 1 and 2. If your data is stored in a PST, all files listed in Table 1 are blocked. If your data resides on an Exchange Server, the system administrator determines which file extensions are categorized as Level 1.
Attachments are accessible but can only be saved to disk.
Other attachments can be opened directly or saved to disk. This is the default for any files not categorized as Level 1 or 2. The restrictions the Outlook update imposes on Level 1 files will undoubtedly force many people to rethink the way they manage email attachments. And in many ways, this is a good thing. The general computing populace is typically either lazy or sloppy when it comes to handling attachments with the respect they deserve.