IP reputation is a trust score assigned to an IP address based on its historical activity. Security systems, email providers, and web services check an IP's reputation before deciding whether to allow, flag, or block incoming traffic. An IP with a poor reputation is associated with spam, malware, attacks, or other abuse.

What Affects IP Reputation

FactorEffect on Reputation
Sending spam or phishing emailsMajor negative — causes blacklisting
Hosting malware or C2 serversSevere — flagged by all major threat intel feeds
Participating in DDoS attacksNegative — IP added to abuse databases
Being part of a VPN or proxy serviceModerate — some services block known VPN exit IPs
Shared hosting with abusive neighboursNegative — shared IPs inherit each other's reputation
No abuse historyNeutral to positive reputation

How IP Reputation Is Used

  • Email delivery — Gmail, Outlook, and other providers check sender IP reputation before accepting messages. Poor reputation means your email lands in spam or gets rejected.
  • Web application firewalls — Block requests from IPs with a known attack history.
  • Content delivery networks — Flag or rate-limit traffic from suspicious IP ranges.
  • Ad platforms — Block conversions from IPs associated with click fraud.

How to Check and Fix Your IP Reputation

  • Use our Blacklist Check to see if your IP appears on major blacklists
  • Check abuse databases like AbuseIPDB and Spamhaus
  • If blacklisted, identify and stop the abusive activity, then follow each blacklist's delisting process
  • Contact your ISP if your IP was flagged for activity you did not initiate — it may indicate a compromised device

People Also Ask

Can my IP reputation affect my business?
Yes significantly. If your server's IP has a poor reputation, your transactional emails (receipts, password resets) will be marked as spam or rejected. Customers will not receive them. Marketing emails will have low deliverability. Some payment processors and fraud prevention tools also flag orders from low-reputation IPs.
Does a VPN give me a bad IP reputation?
It depends on the VPN provider. Many VPN exit IPs are listed in commercial databases that streaming services, banks, and some websites use to detect and block VPN traffic. Using a reputable VPN with a dedicated IP gives you much better reputation control.

Related: IP blacklist | DNSBL | Blacklist Check