Is "30 messages per minute” sending limit per user or per mailbox

Question

Exchange Online sending limits are documented at 30 messages per minute. However, is that limit enforced per user or per mailbox? Specifically:

User A has permission to send email for themselves and has permission to send for User B. User A authenticates to the Graph API and begins sending email for both themselves and for User B.

Is 30 messages per minute limit applied independently to the emails from User A and from User B, or is the limit applied to all the emails that User A sends, regardless of the from mailbox?

Thanks!

Jonathan

Answer 1

Hello @Jonathan Hammer,

Thanks for reaching out!

As per the documentation, sending from another mailbox via permissions is counted for the delegate with rights and not the mailbox that is being sent from.

Documentation reference:

https://learn.microsoft.com/en-us/office365/servicedescriptions/exchange-online-service-description/exchange-online-limits#sending-limits

Hope this helps.

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