Microsoft Defender for Office 365 turns on Promotions tagging for all tenants by late October 2026; the folder move stays an admin setting

Microsoft Defender for Office 365 turns on Promotions tagging for all tenants by late October 2026; the folder move stays an admin setting

2 October 2026 — Microsoft updated Message Center post MC1279093 on 2 October 2026 with the current timetable for a change to how Defender for Office 365 treats promotional e-mail. Marketing mail will be tagged as "promotions" (the label was "Bulk" during preview) and can be moved automatically into a new Promotions folder in users' mailboxes. Microsoft says that at worldwide general availability the tagging is enabled by default for all tenants and will stay that way.

Not yet independently verified. This rests on Microsoft's own Message Center post, read through a public archive; it has been updated seven times since April and its dates have moved before. No independent report had been found at 2026-10-04. We will update this when it can be confirmed, and remove this note.

The timetable

According to the post, worldwide general availability began rolling out in late July 2026 and is expected to complete by late October 2026. For GCC, GCC High and DoD tenants, roll-out also began in late July and is expected to complete by late November 2026. Both dates have moved since earlier versions of the post.

What changes, and what admins control

• Tagging becomes default for every tenant at general availability. Incoming mail classed as promotional receives the promotions classification.
• Moving to a folder happens only where the "Bulk moves enabled" setting is turned on in anti-spam policies. When it is, a Promotions folder is created in user mailboxes and tagged messages are moved there.
• Learning from users: Microsoft says the system learns from users moving messages into or out of the Promotions folder and applies those preferences to future mail.
• Both the tagging and the folder routing can be scoped to pilot security groups for a staged roll-out, and users can create inbox rules that refer to the promotions tag.

Who is affected

All organisations using Defender for Office 365. The change matters most to two groups: IT and security teams that manage mail flow and support users who cannot find messages, and marketing or sales teams in any company whose own newsletters and campaigns reach customers on Microsoft 365, since those messages may now be tagged and filed away.

What to do

1. Decide whether to turn on Bulk moves enabled, and if so, start with a pilot group.
2. Tell users where promotional mail will go and how moving messages trains the filter.
3. Check transport rules and third-party mail tools that rely on bulk-mail classification.
4. Marketing teams: watch engagement from Microsoft 365 recipients after late October, and make sure transactional messages such as invoices and password resets are sent separately from campaigns, so they are not tagged as promotions.

Why it matters for buyers

Changes to mail classification at a provider this large shift what lands in front of business users. It is an operational change for IT and a deliverability change for anyone who sends B2B e-mail.

Sources

• Microsoft 365 Message Center MC1279093 (archive): Promotions tagging and folder in Defender for Office 365 — 2 October 2026