Create An Auto-responder Message:
- Click on My Account.
- Click on Manage Email Accounts.
- Click on Add Auto-Responder for the email address you"d like to add an Auto-responder for.
- Write your Subject and Message.
- Submit.

To disable your message, but keep it for future use, un-check the "On" box.
Note: only one Auto-responder is permitted per email address.