We’re announcing an important change: the Mailbox External Recipient Rate Limit in Exchange Online is being canceled indefinitely at this time.
Customers have shared that this limit creates significant operational challenges, especially given the limited capabilities of bulk sending offerings available today. Your feedback matters, and we’re committed to solutions that balance security and usability without causing unnecessary disruption.
Our goals remain the same:
- Combat abuse of Exchange Online customers, like spam and malicious email activity.
- Prevent misuse of Exchange Online, such as line-of-business (LOB) applications sending bulk email through Exchange Online.
However, we plan to address these issues in ways that are less disruptive to your business workflows. This means smarter, more adaptive approaches that protect the service while respecting your operational needs.
What’s not changing
The Recipient Rate Limit and the Tenant-level External Recipient Rate Limit mentioned in Exchange Online limits remain unchanged by this announcement.
Thank you for your continued feedback and partnership. We’re listening, and we’ll keep working to make Exchange Online secure, reliable, and customer friendly.
Exchange Online Transport Team
