Here you go, hope it helps
Microsoft Outlook has a feature known as “Out of Office Assistant”. This feature enables a user to have e-mail automatically responded to when out of the office regardless if your computer is off or on. You can find this feature under the “Tools” menu in Microsoft Outlook.
Unfortunately this feature requires that your e-mail server be running on Microsoft Exchange to work. Therefore if your server is not running Microsoft Exchange this option will be missing from the Tools Menu.
However, users who do not have Exchange servers can also setup a rule to automatically reply to their messages during a specific date, to do this follow the below steps.
Before following the below steps you will want to create a Microsoft Outlook template which contains your out of office message telling users when you will be away and when you will return.
1. Click Tools and then Rules Wizard.
2. Click New.
3. Select “Check messages when they arrive” and click Next.
4. Check “received in a specified date span” click the date span link in the rule description box and specify the date and click OK and then Next.
5. Check “reply using a specific template” and in the rule description click the template link and point to the template you created earlier. You may need to change the “Look In” to “User Templates in File System”. Once the file has been selected Click Open.
6. Click Finish.
Of course for this to successfully work you will need to have your computer open and Outlook open as well while you are gone.