What is the difference between cold domain reputation and IP reputation?

Domain reputation and IP reputation are separate trust signals that mailbox providers track.

Domain reputation:

Tied to your sending domain (the From address)

Persists regardless of sending infrastructure

Built through engagement over time

Follows you if you change email providers or IPs

Increasingly dominant in modern filtering

IP reputation:

Tied to the IP address sending messages

Can be shared (multiple senders on same IP)

Or dedicated (only you send from that IP)

Changes if you switch sending infrastructure

Still matters but less than historically

For cold email:

Domain reputation matters more than IP for most cold senders

You likely use shared IPs through cold email tools

Focus on protecting domain reputation

IP concerns are largely managed by your sending platform

Monitoring both:

Gmail Postmaster Tools: Domain reputation

Microsoft SNDS: IP reputation

Blocklist monitoring: Both domain and IP lists

Domain reputation is your primary asset to protect in cold email.