I am looking at implementing a New-ThrottlingPolicy and using the RecipientRateLimit, but I am not too sure how it works. Does it limit the unique number of recipients a mailbox can send to?
Lets say that I set the RecipientRateLimit to 10 can the source mailbox send over 10 messages to one other mailbox, or will it fail on the 11th message?
I have read the documentation on New-ThrottlingPolicy and it is pretty vague with:
The RecipientRateLimit parameter specifies the limits on the number of recipients that a user can address in a 24-hour period.
I have also read some information on Some mysteries of Throttling Policy that also did not answer my question. Reading up on the Token bucket map stuff doesn't really help me to understand how things are limited. It's a great technical overview, but doesn't help me to understand if it is unique recipients or not.
The parameter restricts the number of recipient, not the message.
If you set the RecipientRateLimit to 10, the source mailbox can send to no more than 10 recipient per day.
After doing testing I can state that the RecipientRateLimit parameter just counts the number of email addresses on an email and adds that number to a counter. If you communicate with only one person during any 24 hour period after you have sent X number of messages where X is what RecipientRateLimit is set to messages will start to fail.
The accounting is -- this message has Y number of recipients add that to the number currently stored in recipient count number and do a check vs RecipientRateLimit.
It DOES NOT allow a mailbox to send any number of messages to X number of unique recipients in any 24 hour period. I feel like that is a legitimate use case scenario that is not adequately explained in the documentation.