Use automatic (Out of Office) replies from Outlook to tell people you won't be responding right away to their email messages.
To set up automatic replies to other people, select Send replies outside your organization, then add a separate message for that audience.
Note: Sending replies outside your organization will send your automatic reply to every email you receive, including newsletters, advertisements, and potentially, junk email. If you want to send automatic replies to those outside your organization, we recommend choosing Send replies only to contacts.
Note: Automatic replies are not supported for Gmail, Yahoo, or other POP or IMAP accounts.