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
diecknet "Is the limit 2000 recipients per sender or per tenant?"
First I was a bit shocked, and quickly did a check on our tenant, how many unique external recipients we are sending to each day. During the query running in the background, I've double checked the Exchange Online limits page. There it says the following under https://learn.microsoft.com/en-us/office365/servicedescriptions/exchange-online-service-description/exchange-online-limits#sending-limits:
"Recipient rate limit: To discourage the delivery of unsolicited bulk messages, Exchange Online has recipient limits that prevent users and applications from sending large volumes of email. These limits are applied per-user to all outbound and internal messages." (emphasis by me)
At footnote 1 below the corresponding table the example talks about a single user as well.
The_Exchange_Team Maybe some small clarification would be beneficial, like 'Exchange Online enforces a Recipient Rate limit of 10,000 recipients per user' or similar.