You may choose any archive type that is supported by your installed plug-ins to compress your outgoing email attachments with. To choose which archive type is used:
Start Outlook.
Under the Tools menu, click Options.
Choose the CompreXX tab.
In the Compress Attachments Into box, choose the archive type you wish to use.
Tip
If you do not wish your outgoing attachments to be compressed, choose the Don't compress value in the Compress Attachments Into box.
See also: