(Updated) Microsoft Defender for Office 365: Enhancing how we handle promotional mail

Updated October 2, 2026: We have updated the timeline. Thank you for your patience. 

Introduction

We are enhancing how Microsoft Defender for Office 365 identifies and manages promotional email. Promotional messages will be tagged as “promotions” (previously “Bulk” in preview) and can be moved automatically to a new Promotions folder. The system learns from user actions, such as moving messages into or out of the Promotions folder and applies those preferences to future messages. These improvements reduce inbox clutter and help users stay focused while still receiving promotional content they want.

When this will happen

• Public Preview (Limited): We will begin rolling out in mid-April 2026 and expect to complete by mid-May 2026 (previouslyend of April). To be included in the public preview program, send an email to BulkMailPreviews@microsoft.com indicating: Organization name, Tenant ID and your onmicrosoft.com domain (e.g contoso.onmicrosoft.com). Slots are limited and will close on May 15th, 2026.
• General Availability (Worldwide): We will begin rolling out in late July 2026 (previously early July)and expect to complete by late October 2026 (previously late August).
• General Availability (DoD, GCC, GCC High): We will begin rolling out in late July 2026 (previously early July)and expect to complete by late November 2026 (previously mid-September).

How this affects your organization

Who is affected

• All organizations that use Microsoft Defender for Office 365 across Worldwide, GCC, GCC High, and DoD clouds

What will happen

• Incoming promotional messages will be tagged as “promotions.” (previously “Bulk” in private and public preview)
• If the Bulk Moves Enabled setting is turned on, tagged messages will automatically move to a Promotions folder created in user mailboxes.
• The system will learn from user actions when they move messages into or out of the Promotions folder. Future messages will follow the learned behavior.
• Users will be able to create inbox rules that reference the promotions tag.
  • During the Public Preview: Tagging will be opt-in and configured using Exchange transport rules.
  • Folder routing will be enabled through anti-spam policy settings (“Bulk moves enabled”).
  • Both features will be able to be scoped to pilot security groups for a staged rollout.
• At Worldwide General Availability, tagging will be enabled by default for all tenants and will always remain that way.
• For the tagging experience, supported outlooks clients are Outlook on the web and outlook for Windows. Other client such as Outlook for IOS/Android and classic outlook will follow subsequently
• For the promotions folder experiences, Outlook on the web, outlook for Windows, Outlook for IOS/Android and classic outlook are all supported. 

Figure one - Admin configuration for tagging using exchange transport rule (required for public preview opt-In):

 

Figure two - Admin configuration for Bulk moves enabled to provision the promotions folder:

 

Figure three - System tagging of “Promotions” in outlook client and promotions folder (previously  tagged as “Bulk” in private and public preview):

 

Figure four - User inbox rules using the promotions” tag:

 

What you can do to prepare

• To be included in the public preview program, send an email to BulkMailPreviews@microsoft.com indicating: Organization name, Tenant ID and your onmicrosoft.com domain (e.g contoso.onmicrosoft.com). Slots are limited and will close on April 30th, 2026.
• Review your internal mailbox and message handling guidance and update training materials if needed.
• If you plan to participate in the Public Preview, review your Exchange transport rule and anti-spam policy configurations to determine if you want to opt-in.
• Monitor the product documentation. You can review the following: Bulk email detection and bulk complaint level (BCL) in cloud organizations

Compliance considerations

QuestionAnswerDoes the change alter how existing customer data is processed, stored, or accessed?Yes. Incoming email will receive the promotions classification and may be moved automatically to the Promotions folder depending on admin configuration.Does the change introduce or significantly modify AI or ML that interacts with customer data?Yes. The system learns from user actions when they move messages and applies that learning to future similar messages.Does the change include an admin control, and can it be controlled through Entra ID group membership?Yes. Admins can enable or disable Bulk Moves Enabled and can opt in to tagging during Public Preview. These controls can be scoped using existing admin delegation models.Does the change allow a user to enable or disable the feature themselves?Yes. Users can override tagging behavior by moving messages in or out of the Promotions folder, which trains the ML model and adjusts future message handling.