How do ESPs decide which IPs to use for your account?

ESPs use algorithms that consider your sending volume, historical performance, and account tier. New accounts typically start on shared pools with established reputation. As volume grows and track record develops, you may be moved to higher quality pools or offered dedicated IPs.

Some ESPs segment pools by sender quality. Good senders cluster together; problematic senders get isolated to protect the broader infrastructure. Your complaint rates, bounce rates, and engagement metrics influence which pool you occupy.

Enterprise accounts often receive dedicated IP pools by default. Self-serve accounts usually share infrastructure unless they purchase dedicated IPs as an add-on.

The harbor master assigns berths based on the ship's record. Proven vessels get priority docking; unknown ships anchor further out.