What’s the difference between IP and domain blocklists?

IP blocklists track sending server addresses. They identify problematic infrastructure: spam servers, compromised machines, and known bad actors. Being listed means that IP address has been associated with spam, affecting anything sent from it.

Domain blocklists track domain names used in spam: sending domains, link destinations, and branded content. They identify problematic identities regardless of which IP sends messages. Domain reputation travels with you if you change infrastructure.

Both matter for deliverability. IP blocklists affect your sending infrastructure immediately. Domain blocklists affect your brand identity across any infrastructure. Check both IP and **domain reputation** regularly. Problems in either category impact delivery.