Yes this would be very possible.
A number of ways to do this would be:
1) create a VSTO (Visual Studio Tools for Office) addin for outlook. You can listen for events which occur on the inbox which means you can act on an event when a email arrives in the inbox. You can then parse the mail item from the outlook explorer / instance object and check for say the wording in the subject or body. If this is detected you can easily send a response automatically.
The downside here is that a user would have to be in outlook for this to be working.
2) Create an application or service that polls a mail box or public folder in exchange. It could then read emails from within the the mailbox and respond accordingly.
If you can use EWS and not mappi although both work well.
3) Have your butler do it.