mailbox rate limit

The mailbox rate limit tag covers Microsoft's proposed and later canceled per-mailbox external recipient cap for Exchange Online, which would have limited outbound messages to 2,000 external recipients per mailbox in a 24-hour sliding window. Discussions focus on the policy's impact on legitimate email sending, customer pushback, and Microsoft's shift toward adaptive protections. Topics include Exchange Online throttling, outbound spam prevention, tenant-level quotas, and the balance between security and usability. The tag is relevant for IT administrators managing Exchange Online mail flow and compliance.