Setting Out of Office Auto Replies in an Office 365 Shared Mailbox

Log into the Outlook Web App at https://outlook.office365.com using your Office 365 credentials

Click on the profile icon on the top right

Choose Open another mailbox

Type in the email address or name of the Shared Mailbox and select open

Click the settings cog on the top right and then click Automatic replies

Adjust our settings to suits.