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
Hi IanMcDonald In addition to the questions already posed by JSC-HFT about sending all outbound external email via separate security gateways (that’s what we do), I have some additional questions:
1. Does the ERR apply to outbound external emails generated by mailbox level forwarding to external service provider email addresses? E.g. External Sender > Exchange Online Mailbox > ForwardingAddress forward to > External Service Provider Email (e.g. Salesforce, ServiceNow, etc.)
2. Will Microsoft add a report to enable admins to easily identify senders that exceed the ERR? E.g. similar to the existing “mailboxes exceeding receiving limits” report. This is essential for such a major change.