These tools reduce the amount of space required to store attachments and the amount of time required to send messages by applying various compression techniques.
If you use Microsoft Outlook 2010, see Outlook 2010's Default Attachment Size for an issue that may cause issues when using these tools.
The applications on this page are used on the Exchange server and SMTP gateways. Tools for use on user's desktops are listed at Compression Tools for Outlook.
ZipMail for OWA also provides fully integrated automatic and transparent decompression of the Microsoft Outlook Web Access and Webmail Zip attached files.
Mobile Access to Microsoft Exchange Server Data -- Many of the mobile access tools include compression to reduce bandwidth requirements.