MC1158911 Low

Microsoft Exchange Online | SMTP onboarding to App RBAC

  • Admin

Summary AI-generated

Admins can assign SMTP.SendAsApp role to apps via RBAC for group-based mailbox access, streamlining onboarding and eliminating per-mailbox permissions in Exchange Online.

Suggested actions AI-generated

  • Prepare security or distribution groups for mailbox access
  • Plan migration to group-based RBAC assignments
  • Communicate changes to support teams
  • Update internal documentation

Written by Azure OpenAI (gpt-4.1) from the text of the post below. It can be incomplete or wrong; the original post is authoritative.

Original post from Microsoft

[Introduction]

We're simplifying how organizations grant applications permission to send email on behalf of mailboxes. Today, customers must manually assign permissions to each individual mailbox using PowerShell, which is time-consuming and inefficient. With this new capability, admins can assign the SMTP.SendAsApp role to an app through App Role-Based Access Control (RBAC), enabling group-based or scoped access to mailboxes. This simplifies onboarding for SMTP clients using OAuth and provides a scalable, secure, and modern approach to managing mailbox access.

This message is associated with Microsoft 365 Roadmap ID 498356.

[When this will happen:]

  • General Availability (Worldwide): We will begin rolling out early November 2025 and expect to complete by late November 2025.

[How this affects your organization:]

Who is affected:

  • Admins managing SMTP AUTH clients using OAuth in Exchange Online.

What will happen:

  • Admins can assign the SMTP.SendAsApp role to applications via App RBAC.
  • This enables group-based or scoped access to mailboxes.
  • Eliminates the need for per-mailbox permission assignments.
  • Streamlines onboarding for SMTP clients using OAuth.
  • No changes to end-user experience.

[What you can do to prepare:]

[Compliance considerations:]

No compliance considerations identified, review as appropriate for your organization.

Additional details from Microsoft

RoadmapIds
498356
Summary
Microsoft Exchange Online will enable admins to assign the SMTP.SendAsApp role to applications via App RBAC, allowing group-based or scoped mailbox access. This replaces manual per-mailbox permissions, simplifying OAuth SMTP client onboarding. Rollout begins November 2025, with no end-user impact. Prepare by planning group-based access and updating documentation.
Platforms
Desktop, Mac, Web