To set an automatic out of office message when you are away, please refer to the instructions for your type of computer:
If you access your email via Outlook webmail, please refer to Send automatic (out of office) replies in Outlook on the web to set an out of office message.
If you use Mail for Mac or Thunderbird as your email application, you will need to use Outlook webmail to set an out of office message - please refer to Send automatic (out of office) replies in Outlook on the web.