Round-robin is a form of load-balancing across multiple computer servers or IP addresses:
- Requests, or emails that are being sent, go to one of multiple servers (Mail Transfer Agents [MTAs]) in a group.
- The next request is sent to the next server in the group and so on.
- After a request goes to the last server, the next request is sent to the first server and the process starts all over again.
Many senders use this method to balance the delivery of messages, thereby preventing overloading any one server.