Exchange Online to Introduce External Recipient Rate Limit | New Limits for Abuse Prevention

Exchange Online is putting in place a new External Recipient Rate (ERR) Limit, which will take effect in January 2025, as part of the overall 10,000 Recipient Rate Limit. The limit will be enforced in two phases for new and existing tenants to prevent abuse of services, and Exchange Online will not support bulk or high-volume transactional email. The new ERR limit will allow up to 2,000 external recipients within a 24-hour period, which is a sub-limit within the 10,000 Recipient Rate Limit. If an organization surpasses the limit, it could consider Azure Communication Services for Email, which is appropriate for high-volume email sent to recipients outside the organization's domain. The ERR limit will be enforced across all cloud-hosted mailboxes of newly created tenants from January 1, 2025, and within existing tenants from July to December 2025.

The article is available at https://m365admin.handsontek.net/exchange-online-to-introduce-external-recipient-rate-limit/