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Q & A Security · August 15, 2026

Which blacklists matter most?

Spamhaus (SBL, XBL, ZEN) is the most critical — it’s queried by Gmail, Microsoft, Yahoo, and most enterprise mail gateways. Barracuda BRBL and SORBS are also widely used. Being listed on an obscure list with low adoption has minimal real-world impact. DomainScan highlights high-impact listings separately so you know which to prioritize.

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How to Check If Your Domain or IP Is Blacklisted
Being blacklisted on Spamhaus or Barracuda can block 80% of your email overnight. DomainScan checks 50+ blocklists simultaneously for your domain and outbound IP — here's how to read the results and take action.
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How often should I check for blacklisting? My IP is clean but my domain is blacklisted. Does that affect email?