No, there are only four ways to make an automatic reply:
- Transport Rule - but this will bounce with an SMTP status code, not a nice formatted email.
- OOF - but this is labeled an OOF, and only fires once per sender
- Client Side Rule - set-up in Outlook, this only fires when Outlook is running
- Server Side Rule - set-up in Outlook but fires whether Outlook is running or not.
You might be in luck though: it seems a little odd to me that you wouldn't even be able to run Outlook just once against the mailbox in question, so maybe you're assuming that if you make the rule in Outlook it's Client Side? In which case, the Server Side rule option will work for you. To use it, when creating the rule in utlook, make sure the action you choose is "have server reply using a specific message".