Updates to High Volume Email (HVE) Public Preview

Bulk Email (HVE) for Microsoft 365 allows customers to send bulk email primarily to internal recipients without the recipient rate limits in GA (public preview is limited to 100,000 recipients per day per tenant).

HVE comes with the following features: Azure Communication Services (ACS) for emailDeliver high volume transactional, bulk and marketing emails to external recipients. HVE Public Preview It was released April 1, 2024.

Today we are excited to announce several new improvements to the HVE public preview.

Added OAuth support

OAuth support is now available in public preview. Benefits of using OAuth include enhanced security and seamless integration with Microsoft 365. You can use applications or delegated permissions. For instructions on how to enable OAuth for HVE, see: OAuth authentication for bulk email for Microsoft 365.

Improved account settings

In addition to adding support for OAuth, we’ve also improved the Exchange admin center experience for account setup. You can now select your managed domain via the drop-down menu as shown below.

Specifying final names for PowerShell Cmdlet parameters

we are LOBApp account parameter new mail user cmdlet HVE account. An example of final naming is:

New-MailUser -HVEAccount -Name "TestAccount@contoso.onmicrosoft.com" -PrimarySmtpAddress "TestAccount@contoso.com”

The old LOBAppAccount parameter will be available for a while, but will be phased out in the coming weeks.

Federated domain support

Federated domains are now compatible with HVE accounts. To implement HVE for a federated domain, use the following command where contoso.onmicrosoft.com represents the federated domain: You can now include any managed domain in the Name field.

New-MailUser -HVEAccount -Name "TestAccount@contoso.onmicrosoft.com" -PrimarySmtpAddress "TestAccount@contoso.com”

general availability

We are targeting general availability from September 2025 and are expected to be completed by early October 2025. The focus of the public preview is to ensure stability and reliability and introduce additional features such as billing and reporting.

We’d love to hear your feedback about HVE! Please leave your comments and feedback below.

Microsoft 365 Messaging Team