Because the Exchange server sends the messages (not Outlook), Outlook does not need to be open for the reply messages to be sent. The Out of Office Assistant works with the server that is running Microsoft Exchange Server to automatically reply to email messages while you are out of the office. Select the Send replies outside my company to check box, and then complete the information. Set options for replying outside your organization (if enabled by your Microsoft Exchange administrator) Select the I am out of the office between check box, and then set your Start date and End date. Set start and end dates for an Out of Office message In the Reply to message with box, type the text that you want to include in your automatic reply.
To choose an account for which you want to turn on the Out of Office Assistant, select a folder in the account in the folder list before you continue to the next step. Note: If you have multiple Exchange accounts, you must turn the Out of Office Assistant on or off for each account separately.