Relevant Products: Exclaimer Cloud - Signatures for Office 365
You have enabled the Advanced Threat Protection (ATP) Safe Attachment and Dynamic Delivery features and find that messages routed via Exclaimer Cloud are either delayed or not delivered.
The following statement was provided by Microsoft:
- Log on to the Office 365 Portal as a Global Administrator.
- Open the admin center.
- Click admin centers and select Exchange.
- Select mail flow and then rules.
- Edit the Identify messages to send to Exclaimer Cloud rule.
- Under Do the following field, click add action
- Select Modify the message properties, and then set a message header as follows:
Save the transport rule.