Updated August 2, 2023: We have updated the rollout timeline below. Thank you for your patience.
Purview Messaging Encryption supports customized branding templates for encrypted mail sent to external recipients. The functionality is being brought to Data Loss Prevention policy from Exchange mail flow rule. In addition, DLP policies provide additional configuration to control whether Microsoft 365 external recipients will be able to view the encrypted mail inline using Outlook or the encrypted portal experience.
This message is associated with Microsoft 365 Roadmap ID 117489
[When this will happen:]
We will begin rolling out mid-August 2023 (previously late July) and expect to complete by mid-September 2023 (previously late August).
[How this will affect your organization:]
There is no impact to existing mail flow rule in Exchange online that are already setup in Exchange Admin Center. Administrators can choose to now configure new DLP policy in the Microsoft 365 compliance center to apply customized branding templates to encrypted mail instead of configuring mail flow rules in Exchange Admin Center. DLP policy will have higher preference and therefore override mail flow rule in applying customized branding templates to encrypted mail. (Configuration of the custom branding template still requires admins to use Exchange powershell. See Add your brand to encrypted messages – Microsoft Purview (compliance) | Microsoft Learn for details
[What you need to do to prepare:]
If you are interested in applying custom branding, get started with Data Loss Prevention in the Microsoft Purview compliance portal.
