How do I set up an out going message when I am not in the office?

Trouble wrote:

How do I set up an out going message in mail when I am not in the office? An out of office message.

https://www.macworld.co.uk/how-to/mac-software/how-set-out-of-office-mac-mail-3537337/

It is a bad idea to create an auto reply email in an email client. Spammers, phishers, spoofed email addresses, etc. will get the auto reply. Log into your email server's web page and see if they offer a safe auto reply option at the server level.