How do I set up an out-of-office or vacation autoresponder in cPanel?

In cPanel, go to the "Email" section and select "Autoresponders". Click "Add Autoresponder". Fill in the necessary details such as the interval, email username, domain, from address, subject, and the body, i.e. autoresponse message. Set the start and stop time for the autoresponder and click "Create/Modify".

Use this as an example:

Interval: 24
Email: Enter your username. If your email address is "[e-mail]" enter "you" as the username.
Domain: Select the domain you want the autoresponder for. If your domain is yourdomain.com, select that.
Front: Enter your complete email address.
Subject: Your autoresponse email subject.
Body: Your autoresponse message.
(If your email contains HTML, remember to select the "This message contains HTML" checkbox. Otherwise leave it unchecked.)
Start: Immediately 
Stop: Click Custom and select the date when the autoresponder must end.

Important: Remember to replace yourdomain.com with your actual domain.

Good to Know: Regularly update your autoresponders to provide accurate information, especially if the return date or contact details change.