Microsoft 365 Message Center item MC1454397
MC1454397 - Updates to Tenant External Recipient Rate Limit (TERRL) Quotas for New, Trial, and Education Tenants
Tenant External Recipient Rate Limit (TERRL) quotas in Exchange Online will change starting mid-September 2026 for new, trial, and EDU tenants, adjusting limits based on tenant age and license type. Trial tenant quotas reduce to 500 recipients daily; EDU quotas use a new formula. Exceeding limits blocks outbound messages.
- Message Center ID
- MC1454397
- Category
- stay Informed
- Severity
- normal
- Services
- Microsoft 365 suite
- Tags
- Feature update, User impact, Admin impact
- Published
- 2026-08-14
- Last updated
- 2026-08-14
- Expires
- 2026-11-14
[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 [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 quota31–60 days: 25% of standard calculated quotaMore than 60 days: 100% of standard calculated quotaTrial tenants:Daily TERRL quota reduced from 5,000 to 500 external recipientsTenants with free EDU licenses (e.g. A1 licenses):New formula applied: 500 × (Purchased Email Licenses^0.7 + Free EDU Licenses^0.3) + 9500Free EDU licenses contribute to the quota at a lower weighting than purchased licensesTenants without free EDU licenses:Existing formula remains unchanged: 500 × (Purchased Email Licenses^0.7) + 9500If a tenant exceeds its quota:Additional outbound messages to external recipients will be blocked until usage falls below the rolling 24-hour limitSenders will receive one of the following Non-Delivery Reports (NDRs):Trial tenants: 550 5.7.232 — Message blocked due to trial tenant external recipient limitNon-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 quotaOutbound recipient volumePercentage of quota consumedBlocked recipients (if any)TERRL enforcement statusIf 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.