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Microsoft 365 Blog
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High Volume Email Is Now Available in Exchange Online

JeremyCarlson's avatar
JeremyCarlson
Icon for Microsoft rankMicrosoft
Mar 31, 2026

Reliable email remains one of the most critical ways organizations communicate with employees at scale especially for operational, time‑sensitive messages like payroll notifications, security advisories, and IT service alerts. Yet for many organizations, delivering these messages has meant living with tradeoffs: maintaining on‑premises Exchange servers, relying on third‑party SMTP relay services, or repurposing user mailboxes in ways they were never designed to support.

Today, that changes. High Volume Email (HVE) is now generally available in Exchange Online, delivering a purpose‑built, tenant‑native way for applications and devices to send large volumes of internal email reliably, securely, and at scale without impacting user mailboxes or Exchange Online service health.

Why High Volume Email (HVE)

Exchange Online is optimized for person‑to‑person communication. Its built‑in limits and protections are intentional. They help preserve reliability, trust, and service health for human workflows. But those same protections can make automated, high‑volume scenarios for internal emails difficult to support cleanly.

High Volume Email was designed specifically to meet this need.

HVE is a native Exchange Online capability built for application‑to‑person messaging. It uses dedicated HVE accounts rather than user or shared mailboxes, helping to ensure automated traffic is clearly separated from human communication. For Exchange Online mail flows, messages remain entirely within Microsoft infrastructure and inherit Exchange Online’s existing security, compliance, and policy boundaries. 

For customers modernizing their environments, this means highvolume system email no longer requires legacy infrastructure or unsupported workarounds. Critical application workflows can move fully into Microsoft 365 without sacrificing reliability or governance. 

Common Scenarios

High Volume Email is designed specifically for transactional and operational messaging, not marketing campaigns. It does not include campaign tooling, templates, or engagement tracking. Instead, it supports the high‑trust, high‑reliability use cases that organizations depend on every day.

Common scenarios include:

  • Payroll and HR system notifications
  • IT monitoring and service alerts
  • Business and line‑of‑business application messaging
  • Device‑driven workflows, such as printers and scanners
  • Security and compliance notifications

 

By providing a dedicated service for these scenarios, High Volume Email allows organizations to send large volumes of internal email without hitting recipient rate limits or risking service health issues associated with user mailboxes.

General Availability and Pricing

High Volume Email is now generally available in Exchange Online for sending email to internal recipients. Usage will be metered starting June 1, 2026 based on the number of expanded email recipients, with pricing set at $42 per one million recipients through Microsoft commerce (equivalent to $0.000042 per one recipient).

This pricing model is intentional and aligns usage with service protection, helping maintain fairness and reliability for high‑volume automated email scenarios.

How to Get Started

Getting started with High Volume Email is straightforward. Administrators can explore and configure the service directly in the Exchange admin center, where High Volume Email is available under Mail flow. Learn more here.

Because HVE is tenant‑native and built into Exchange Online, organizations can deploy it without introducing new infrastructure or third‑party dependencies making it easier to modernize application architectures and retire legacy email systems.

Move Critical Email Workflows Fully into Microsoft 365

High Volume Email brings a long‑needed capability to Exchange Online: a scalable, secure, and governed way to send high‑volume system email designed specifically for how modern organizations operate.

By separating automated messaging from human communication, High Volume Email protects service health, strengthens governance, and simplifies infrastructure while keeping critical communications entirely within Microsoft 365.

If you’re looking to retire legacy SMTP relay, help reduce reliance on third‑party services, or modernize how your applications communicate with employees, explore High Volume Email in the Exchange admin center today.

Updated Mar 31, 2026
Version 1.0

4 Comments

  • Rolf Tröndle's avatar
    Rolf Tröndle
    Copper Contributor

    with pricing set at $42 per one million recipients through Microsoft commerce ... please specify that this is a PAYG configuration using billing policies in M365 Admincenter. I couldn't find anything about that in the documentation or blog posts. 

    https://admin.cloud.microsoft/?#/paygplatform/paygservices

     

  • Grzegor's avatar
    Grzegor
    Copper Contributor

    Biggest problem with this service is that it only allows mails to Internals.

  • DaithiG's avatar
    DaithiG
    Steel Contributor

    As a small company would need some of these accounts for SMTP, this would just push us to a 3rd party. I know it's for High Volume but it really is a SMTP replacement and a pity there's no daily allowance before charges 

  • I am currently evaluating adoption for this feature but have a few concerns:


    1. It is unclear how we will be billed for this service.
    Based on MC1243552 it is still free and will start being metered on June 1st.
    Will it appears as an M365 pay as you go service that can be linked to an Azure Subscription, if so, when?

    2. Will there be any change to the Service Limits published in : https://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/high-volume-mails-m365#service-limits now that GA is announced?

    3. OAuth guidance from : https://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/oauth-high-volume-mails-m365 is vague about scoping the Entra ID App.
    It advises we apply 'Office 365 Exchange Online' Mail.Send API Permissions to Entra ID App Registration, but provides no guidance on how Application Type permissions could be scoped to only be used for HVE Accounts.
    Allowed Applications explains how the HVE Account can restrict which apps can use it, but how does this leave all the other mailboxes in our tenant?
    We could restrict app scope via Application Access Policies, but this is a legacy feature and it does not scale well with HVE Accounts which cannot be added to MailEnabled Groups leading to 1:1 Application -> HVEAccount pairing and many Entra ID Apps and application access policies created.