How to set up autoreply for a shared mailbox in Office 365

It's ok for normal user mailbox (licensed) but not shared mailbox (unlicensed).

Yes. This was what I followed. I could only see "Send automatic replies" there for licensed account but not shared mailbox. 

Hi Sam,

To set the auto reply for the shared mailbox, follow the steps below:

1. Sign intoExchange admin center (https://outlook.office365.com/ecp) with your Office 365 admin account.
2. Click your picture on the upper right corner of the page, select Another userand double click the shared mailbox. Navigate toorganize email –  automatic replies. Select Send automatic replies and type the content for the replies for internal users and external users respectively. Click Save at last.

Please let me know if you need further assistance.

Regards,

Barry

Hi Sam,

Could you give us a screenshot of the organize email interface for a better understanding?

Regards,

Barry

Hi Sam,

Could you give us a screenshot of the Options interface on your side?

Please refer to the below screenshot to check if you can find the Automatic replies button.

Also, here is an article for your reference:

https://support.office.com/en-us/article/Automatic-replies-formerly-Out-of-office-assistant-48d40166-0129-4653-98f1-eb85f9bd8c20

Regards,

Barry