You can set out of office (auto replying rule) in Outlook with below workarounds: Set out of office (automatic reply) with Out of Office Assistant with Exchange Account (If you need to set a rule for automatically replying messages via Outlook, normally you have to compose a new message and save as an Outlook template, next set a rule which will filter messages based on special criteria and reply with the specific template, and then select exceptions if necessary. Actually Kutools for Outlook's Auto Reply utility can help you automatically reply messages easily.
If you are using an Exchange account, you can auto reply a specified message for the received emails with setting the Out of Office Assistant while you are away. In the Mail view, select the exchange account on the Navigation Pane, and click File If your outlook haven’t connected to an Exchange Server, the above method will not work.
To reset, simply turn the Automatic Reply off and then back on again.
Note 2: By default, Exchange does not allow Automatic Replies and OOF messages to the Internet.
In this case, you might want to let people know why you're not responding to their emails even though you have received the emails.After automatic replies are turned on, they’ll be sent once to each sender.If you have a Microsoft Exchange-based email account, for example, a Microsoft Office 365 work or school account, and you use Outlook and Outlook Web App, you can use either one to manage your automatic replies.Note: using server-side rules allows you to get round the one reply to one sender limitation.You do not need to have Outlook or OWA open for the rule to work.The process leverages Outlook Rules and Alerts to mimic the Out of Office Assistant functionality, and although it may not be as graceful or easy to enable, it does get the job done.