Update Aug 13, 2026: To further 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 cal...
Updated Aug 25, 2026
Version 30.0
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Based on the formula and licenses owned by my company, we can email to ~26 external recipients per license. If we had 100K licenses, we'd be limited to 15 external recipients per license.
Conclusion: More money paid to MS in license fees results in increased restrictions per license.
Action plan: Find a way to give MS less money
100% agree with you Rob_R ... a tenant consisting of single user with a relevant EXO license can send to 10k external recipients, which at RRP costs is £3.10 per month on Plan 1.
A customer that has 100k of the same licenses (assuming no volume discount), would be paying £310k per month, for 15 external recipients per user.
In what business model does that work anywhere in the world ... pay £3.7m a year to get 0.0015% of the same service for someone that pays £37.
Madness.