Microsoft has announced that High Volume Email HVE in Microsoft 365 will continue to support basic authentication until September 2028 to give businesses more time to switch to modern authentication methods, such as OAuth . The Redmond giant also announced that it was removing some functionality of HVE, which we will get onto in a moment. Beginning from next month, Microsoft will no longer allow you to use HVE with external recipients. Going forward, it will be for exclusively sending emails...
