If you don’t have an Exchange server you can create an auto-reply template:
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.
Click on the a specific template link to browse for the auto-reply email template. The template should be in the User Templates in File System from the Look In drop down box
Name your rule and click the Finish button.
Please note that 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)