onmicrosoft

The onmicrosoft tag covers Microsoft's default tenant domain (onmicrosoft.com) and the MOERA (Microsoft Online Email Routing Address) namespace. Recent discussions focus on Microsoft's announced throttle limiting outbound email from onmicrosoft.com addresses to 100 external recipients per organization per 24-hour rolling window, with staged enforcement starting in October 2025. Topics include the rationale behind the cap—curbing abuse and protecting shared reputation—and the push for tenants to migrate to custom domains for production email. The tag is relevant for Microsoft 365 administrators and IT professionals managing tenant configuration, email routing, and compliance with the upcoming restrictions.