You can configure the server to automatically reply to new emails, either temporarily to notify the sender that you're away on vacation, or permanently to let the sender know that you will responder to their message soon.
An autoresponder can be configured quite easily. First login to the client area, then under your hosting plan, click on Autoresponders. Then click on the Create Autoresponder, fill in message you'd like to response with and adjust any of the options, then click Save.
