【Important】Change in Outbound Restriction Specifications for Email DLP and Request to Review Forwarding Settings (Gmail)

Target

• Customers using Email DLP. (Customers who have set up forwarding in Gmail)

Content

Thank you for using HENNGE One.
Recently, we have confirmed cases where Email DLP's sending restrictions were applied to a large volume of emails sent using sub-address formats, which are presumed to be after automatic forwarding or Google Groups expansion, resulting in an impact on customers' email delivery.

These emails are inherently not subject to filtering by Email DLP. In addition, after automatic forwarding or Google Groups expansion, the original sender address is rewritten to a sub-address format by Google Workspace before delivery. Therefore, senders cannot check these emails in the Email DLP sending history.

Furthermore, in environments where users can set up automatic forwarding themselves, external forwarding that is not visible to the admin may occur, leading to risks in email governance.

Therefore, if you are delivering emails via Email DLP after automatic forwarding or Google Groups expansion, please refer to the following procedure and consider taking appropriate action.

• For customers who do not require Gmail automatic forwarding
• For customers who wish to continue Gmail automatic forwarding

For more information about the sub-address mechanism and details about Email DLP sending restrictions, please refer to the following related articles.

• [Email DLP] What is a sub-address?
• [Email DLP] About sending restrictions for the service
   

Procedure

Disabling automatic forwarding

Procedure for admins to disable external email forwarding

1. Access the [Google Admin console] in Google Workspace.
   
2. [Apps] – [Google Workspace] – [Gmail] – [End User Access]
   
3. Uncheck [Allow users to automatically forward received emails to another email address] under [Automatic Forwarding], then Save.
   
4. Confirm that users cannot configure forwarding settings in their Gmail screen. 

Recommended settings for users who continue email forwarding

Procedure for admins to configure external email forwarding

1. Access the [Google Admin console] in Google Workspace.
   
2. [Apps] – [Google Workspace] – [Gmail] – [Email Routing Settings]
   
3. Select [Email forwarding using recipient address map] – [Settings].
   
4. In the [Email forwarding using recipient address map] settings, enter the following information.
   ・[Email forwarding using recipient address map]: Any value
   ・[To forward emails, map the original recipient to the new recipient]
   　・[Address]: Source email address
   　・[Mapped address]: Destination email address
   ・[Target emails]: Only emails received from external sources
   ・[Routing options]: Route to the original recipient as well
   ・[Options]: Add X-Gm-Original-Tp header 
   
5. Confirm that forwarded emails are not routed through Email DLP.