How do large senders distribute traffic across IPs?

Large senders distribute traffic across multiple IPs to control volume, manage reputation, and avoid overwhelming receiving servers. They assign different types of traffic to different IP pools such as transactional mail, marketing mail, or regional streams.

This distribution happens through internal routing logic within the MTA which selects an appropriate IP based on traffic type, load, and reputation signals. It is like sending multiple ships out of a port rather than placing all cargo on one vessel.