6/25/2025 Important update regarding the cloud hosted Mailbox External Recipient Rate Limit: In order to reduce the impact on customers, Microsoft has again decided to delay the rollout of the cloud ...
Updated Jun 25, 2025
Version 14.0
Blog Post
For cloud-hosted mailboxes that are using 3rd parties email gateways, we will account (and not inappropriately count) for these scenarios. We won’t count intratenant mail against the External Recipient Rate Limit even if it routes out of ExO then back in. We also won’t double-count messages or recipients when the message is sent out of ExO, routes back in, then routes out of ExO again and to the final destination. However, if your cloud hosted mailbox routes anyexternal mail to a 3rd party gateway, then these mails to external recipients would be counted.
IanMcDonald just to make sure I got it right, could you please confirm the following?
mailto:email address removed for privacy reasons sends to 100 recipients -> email forwarded via connector, SMTP relay -> email received back through inbound connector -> Exchange sends email to recipients
mailto:email address removed for privacy reasons sends to 200 recipients -> email forwarded via connector, SMTP relay -> email received back through inbound connector -> Exchange sends email to recipients
In this case, user1 will have 100 recipients used and user2 will have 200. There is no way in which the relay through the connector is affected, regardless of how this is performed/set up. The limit is strictly per sender mailbox, and does not take the originating IP or anything else into account.
I just need to make surehttps://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/use-connectors-to-configure-mail-flow/set-up-connectors-to-route-mail will 100% not be affected.