MC1454397 - (Updated) Updates to Tenant External Recipient Rate Limit (TERRL) Quotas for New, Trial, and Education Tenants

Microsoft 365 Message Center announcement MC1454397.

Message Center ID

MC1454397

Category

stay Informed

Severity

normal

Services

Microsoft 365 suite

Tags

Updated message, Feature update, User impact, Admin impact

Published

2026-08-14

Last updated

2026-09-29

Expires

2026-12-31

Updated September 29, 2026: We have updated the timeline. Thank you for your patience. [What and Why:] To strengthen protection against abuse and ensure fair use of Exchange Online resources, we are updating how the Tenant External Recipient Rate Limit (TERRL) quota is calculated for certain tenants. These changes improve how quotas account for tenant age (how long the tenant has existed since creation), trial subscriptions, and educational organizations using free Education (EDU) licenses. [Rollout Schedule:] General Availability (Worldwide): Rolling out beginning mid-September 2026 and expected to complete by end of November 2026 . [Impact on Your Organization:] Who is affected: Newly created tenants (first 60 days) Trial tenants Educational organizations with free EDU licenses Platforms/Services: Exchange Online Exchange admin center (EAC) What will happen: TERRL quota calculations will change based on tenant status and licensing. New tenant quotas (based on tenant age): Less than 31 days: 10% of standard calculated quota 31–60 days: 25% of standard calculated quota More than 60 days: 100% of standard calculated quota Trial tenants: Daily TERRL quota reduced from 5,000 to 500 external recipients Tenants with free EDU licenses (e.g. A1 licenses): New formula applied: 500 × (Purchased Email Licenses^0.7 + Free EDU Licenses^0.3) + 9500 Free EDU licenses contribute to the quota at a lower weighting than purchased licenses Tenants without free EDU licenses: Existing formula remains unchanged: 500 × (Purchased Email Licenses^0.7) + 9500 If a tenant exceeds its quota: Additional outbound messages to external recipients will be blocked until usage falls below the rolling 24-hour limit Senders will receive one of the following Non-Delivery Reports (NDRs): Trial tenants: 550 5.7.232 — Message blocked due to trial tenant external recipient limit Non-trial tenants: 550 5.7.233 — Message blocked due to tenant external recipient limit [Action Required / Recommendations:] No immediate action is required. Recommended actions: Review the Tenant Outbound External Recipients Rate report in the Exchange admin center: EAC > Reports > Mail flow > Tenant Outbound External Recipients Rate. Monitor: Current TERRL quota Outbound recipient volume Percentage of quota consumed Blocked recipients (if any) TERRL enforcement status If your organization regularly operates near or above quota consider migrating high-volume, application-driven outbound email to a third-party bulk email service or purchasing more licenses to cover your volume needs. Learn more: Introducing Exchange Online Tenant Outbound Email Limits [Compliance considerations:] No compliance considerations identified, review as appropriate for your organization.