Email Blacklist

Blacklists are maintained by organizations that track spam. When your IP or domain is reported:

• ●The blacklist operator investigates
• ●If spam is confirmed, you're added to the list
• ●ISPs query these lists in real-time
• ●Emails from listed IPs/domains are blocked or filtered

Major blacklists include Spamhaus, Barracuda, SORBS, and SpamCop. Different ISPs check different lists, being on one doesn't mean you're blocked everywhere.

Common causes:

• ●High spam complaint rates
• ●Hitting spam traps (old addresses used to catch spammers)
• ●Sudden volume spikes
• ●Sending to purchased/scraped lists
• ●Compromised account sending spam
• ●Bouncing to invalid addresses repeatedly

Sometimes unfair:

• ●Shared IP contaminated by other sender
• ●Inherited reputation from previous domain owner
• ●Overly aggressive spam trap operators

Check multiple blacklists regularly:

MXToolbox Blacklist Check Queries 100+ blacklists simultaneously. Free and comprehensive.

MultiRBL Another multi-blacklist checker with detailed results.

Individual blacklist sites

• ●Spamhaus: check.spamhaus.org
• ●Barracuda: barracudacentral.org/lookups

Set up monitoring alerts so you know immediately if you're listed.

Each blacklist has its own removal process:

• ●Identify the blacklist - Find which ones you're on
• ●Fix the root cause - Don't request removal until you've stopped the spam
• ●Submit delisting request - Most have online forms
• ●Wait - Some auto-expire after days; others require review
• ●Document changes - Be ready to explain what you fixed

Major blacklist delisting:

• ●Spamhaus: Usually requires email to their team explaining fixes
• ●Barracuda: Self-service removal with explanation
• ●SORBS: Time-based expiration for most listings