MC1243552 - High Volume Email for Microsoft 365 now generally available

Updated March 31, 2026: We have updated the content. Thank you for your patience. 

Introduction

Exchange Online includes email‑sending limits based on three factors: recipient rate limit, recipient limit, and message rate limit. To support customers whose internal communication needs exceed these standard limits, we are introducing High Volume Email (HVE) for Microsoft 365. HVE is designed for large‑scale internal communications and integrates with business applications and devices to support operational and mass‑mailing scenarios. It uses a transactional pricing model based on the number of recipients.

HVE is currently available at no additional cost during Public Preview.cost, with metered billing starting June 1, 2026. Pricing for General Availability (GA) will be announced with the GA release, and billing will begin in May 2026 following a free promotional period after GA in March 2026.information is now published. For more information, see High Volume Email Is Now Available in Exchange Online.

This message is associated with Microsoft 365 Roadmap ID 382633.

When this will happen

• Public Preview: Available now.
• General Availability (worldwide): Rollout begins in late March 2026 Rolling out now and rollout is expected to complete early April 2026.2026.

How this affects your organization

Who is affected

• Admins managing Exchange Online mail flow and reporting
• Organizations with large-scale internal email distribution needs

What will happen

• A new High Volume Email page will appear under Mail flow in the Exchange admin center.
• Admins can create and manage Mail User accounts enabled for HVE.
• HVE accounts use a dedicated SMTP endpoint for high-volume sending.
• A new High Volume Email report will appear under Reports > Mail flow to help admins monitor HVE usage per account.
• HVE is opt‑in; it does not modify default sending limits or existing mail flow behavior.

Screenshot 1 - Create new HVE specific accounts: 

Screenshot 2 - Manage HVE accounts, including assigned billing policies:

What you can do to prepare

No action is required to prepare for this change.

You may want to:

• Review and update any internal documentation that describes email‑sending processes.
• Learn more about setup and configuration: Manage high volume emails for Microsoft 365 Public preview | Mail flow best practices | Exchange Online | Microsoft Learn

Compliance considerations

No compliance considerations identified. Review as appropriate for your organization.