Approximate Message Sizes

By default, Exchange calculates the exact size of each message. You can increase the speed of message retrieval for clients that do not require exact message size reports by enabling the server to approximate message sizes.

To approximate message sizes:

1. Start System Manager
   on the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
2. Navigate to IMAP4.

   System Manager

   1. Administrative Groups
   2. Administrative group
   3. Servers
   4. Server
   5. Protocols
   6. IMAP4
3. In the console tree, right-click a virtual server, and then click Properties.
4. On the General tab, click Enable fast message retrieval.