I want to set an out of office message but File > Info does not show Automatic Replies at all. I use Outlook 365 with a Gmail account. Where did it go?

Automatic Replies is only available for accounts that run on Exchange or Microsoft 365. Gmail, Yahoo and other IMAP or POP accounts do not support it in Outlook, so the button is not shown.

For a Gmail account, set it in Gmail itself. Open Gmail on the web, click the gear, See all settings, scroll to Vacation responder and turn it on with your dates and message.

If you want to do it in Outlook for an IMAP account, the only option is a rule with the action "reply using a specific template". That rule runs only while Outlook is open on your computer, so the Gmail vacation responder is the better choice.

Set it in Gmail and it works. Thanks.