Amazon continues to tighten their policy on buyer-seller messaging; therefore it is important to ensure you are not exceeding the allowed quota when sending messages to buyers. 

The Quota

To ensure you are not exceeding, we will manage your quota when using Feedback. 

The quota calculation is: 
(Number of orders for the past 7 days * 4) / 7 + 500

That means you can send 4 times more messages than your orders for the last 7 days, plus another 500.

Reaching Your Quota

When you reach 80% of your quota, you will see a message within your account as follows:

You have reached 80% of your Amazon message quota. If you hit the limit, messages will be scheduled to send over several days, ensuring you stay within the quota. This ensures that you can still send support messages.

Monitoring the Quota

You will see an Amazon Feedback Quota section inside your Feedback dashboard

Messages Sent (Last 24h) The number of messages sent for each channel
Message Quota The number of messages that can be sent for each order 
Average Orders (Last 7 days) The average number of orders received through each channel over the last 7 days
Quota Usage The number of messages sent out of the channel quota