Exchange Online Update: Mailbox External Recipient Rate Limit is Canceled

The Mailbox External Recipient Rate Limit was introduced in Exchange Online to prevent misuse of the service, such as spam or bulk emails sent by compromised accounts or line-of-business applications.

While it served a security purpose, it often ended up impacting business workflows such as notifications, alerts, and line-of-business applications.

Microsoft listened to this feedback and has now decided to cancel this limit indefinitely — and this is welcome news for many organizations.

𝑺𝒕𝒊𝒍𝒍 𝒊𝒏 𝒆𝒇𝒇𝒆𝒄𝒕:
These controls are unchanged and continue to protect your environment:

✅ Recipient Rate Limit
✅ Tenant-level External Recipient Rate Limit