How can you make a rule to auto reply when you are out of the office. Outlook doesn't have this kind of rule.
- Create an auto-reply email template and save it as an Outlook template
- Create a message reply to send an automatic reply to your emails
- In Tools | Rules and Alerts create a new rule (Start from a blank rule, click Check messages when they arrive)
- In Which condition(s) do you want to check? window select the Sent Only To Me
- In What do you want to do with the message? window select the Reply using a specific template check box. In the Select A Reply Template dialog box, click the email template that you created as auto-reply template.
Edit: this rule will send the reply only one time to each sender (Outlook will save a list of email addresses it has responded to prevent sending repetitive replies, but if the Outlook is closed the list is deleted)
Use Tools -> Rules and Alerts to create a reply rule for received messages.
The above link will lead you to a step by step guide to setting up out of office replies on both Outlook 2003 and 2007.