Step 1: Go to "File"
Step 2: Select "Automatic Replies"
Step 3: Select "Send Automatic Replies" then type your message in the box provided.
Note: You can then set your replies for a desired time period by selecting
"Only send during this time range" and adjusting your "Start" and "End" times.
REMEMBER to type the reply in both the "Inside My Organization" so that everyone receives this message: