Dear Sir/Madam,
Thank you for your email. I am currently away from my desk and may not be able to respond immediately.
Please be informed that I am available to respond to messages during my regular working hours: Monday to Saturday, from 9:00 AM to 10:00 PM (local time). Your message is important to me, and I will respond as soon as I am able.
Thank you for your understanding.
Kind regards.