How to allow encrypted Microsoft Purview messages in MetaDefender Email Gateway Security?
This article applies to all MetaDefender Email Gateway Security V4 and V5 releases deployed on Windows Systems.
Issue:
Microsoft Purview emails that contain .rpmsg attachments are encrypted and can only be accessed by the intended recipient.
Since .rpmsg attachments do not have an option for password entry, they are often detected as encrypted documents by MetaDefender Core, causing them to be blocked when processed by MetaDefender Email Gateway Security.
Root Cause:
MetaDefender Core identifies .rpmsg files as encrypted content, which triggers the default security policy to block them during email scanning.
Remediation Steps:
To allow Microsoft Purview emails with .rpmsg attachments to pass through MetaDefender Email Gateway Security, follow these steps to allowlist the file type in MetaDefender Core:
Open MetaDefender Core configuration settings.
Navigate to:
Allowlist→Allowlist by Filetype→Encrypted Documents.
Add a new allowlist entry:
- Type: RPMSG
Save the configuration changes.
With this configuration, .rpmsg attachments will be allowlisted, and Microsoft Purview emails will no longer be blocked by MetaDefender Email Gateway Security for encryption-related reasons.
In the unlikely event that you have followed the instructions above but are Unable to allow encrypted Microsoft Purview messages in MetaDefender Email Gateway Security, please proceed to log a support case or chatting with our support engineer.
