How does IP choice affect sender reputation?

Mailbox providers track reputation at both the IP level and the domain level. Your IP choice determines whether you own that reputation independently or share it with others.

On a shared IP, you inherit the pool's existing reputation. This helps new senders get started but means you're affected by neighbors' behavior. On a dedicated IP, you start from zero and build reputation through your own sending patterns, engagement rates, and complaint volumes.

Domain reputation has become increasingly important. Even with a perfect IP, a domain with poor history will struggle. Conversely, strong domain reputation can partially compensate for IP issues. Modern deliverability requires attention to both.

The IP is the ship; the domain is the flag you fly. Port authorities check both before granting entry.