KB ID 0001480 Problem If you are used to running ‘on-prem’ Exchange then allowing an IP/Hostname to relay mail (sent mail through without authenticating) it’s handy for things like older multifunction scanners, or applications that need to send emails. Now you SHOULD be sending mail through Office 365 ‘authenticated’, but that’s not always possible. Solution From Office 365,Launch The Exchange admin console. Mail flow > Connections > Add. From: Your Organisations email server. To: Office 365 Give the connector a sensible name > Next. Enter the PUBLIC IP or PUBLIC...