Almost two years after it first previewed, Microsoft is making the High-Volume Email (HVE) solution generally available in March 2026. HVE runs on a pay-as-you-go basis, but Microsoft won’t start charging tenants for sending email until May 2026. Two months should be enough for people to decide if they want to use HVE for internal communications as it has no ability to send external email.
After considering customer feedback, Microsoft cancelled the mailbox external recipient rate limit for Exchange Online. The idea behind the new limit was simple – it makes life more difficult for spammers to use Exchange Online as a platform. Unhappily, customers didn’t like losing the ability to send relatively small amounts of external email for different reasons. C’est la vie.
On Oct 14, 2025, Exchange 2019 and 2016 reach end-of-life and Exchange SE becomes the only supported on-premises Exchange server. In other news, we discuss Microsoft guidance for moving to cloud first identity, HVE and ECS and the extension of basic authentication support to September 2028, the introduction of auto-archiving for Exchange Online, and why Microsoft is deprecating the Contact object from Exchange Online.
This article covers how to use HVE with Azure Automation to send email. HVE is Exchange Online’s High Volume Email solution for internal communications. In the discussion, we cover how to retrieve credentials from Azure Key Vault, how to retrieve data from a web page, and how to bring everything together in a message submitted to HVE.
HVE and ECS are two competing Microsoft Cloud Email Services. At least, they seem to compete. In reality, HVE and ECS serve different target audiences. HVE is all about internal email services for apps and devices while ECS is for high volume external mailings like customer newsletters. We tested both services by sending subscription reminder notifications to Office 365 for IT Pros readers.