Answer:
In Microsoft Office Outlook 2003, a new offline folder file format is introduced that offers greater storage capacity for items and folders and supports multilingual Unicode data. An offline file folder is used to keep a local copy of your Exchange Server mailbox on your computer. The items in your .ost file are synchronized with the server when a connection is available.Steps for offline file folder:-1. On the File menu, click Work Offline. 2. Select or clear the Prompt me at startup so I may choose to work offline or online check box, and then click OK. If you clear the check box, Outlook will automatically start offline if a connection to the server is not available.3. Click Yes to copy the data from the server to your new Offline Folder file (.ost).