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.