Getting Off Email Blacklists

Email blacklists are databases of IP addresses and domains known to send spam. If your IP or domain gets blacklisted, your emails may be blocked or sent to spam folders. This guide explains how to check if you're blacklisted and how to get removed.

Why You Got Blacklisted

Common reasons for blacklisting include:

• Compromised account — A hacked email account sending spam
• Malware infection — Server compromised and used for spam
• Poor list hygiene — Sending to old/invalid addresses that became spam traps
• High complaint rate — Too many recipients marking your email as spam
• Shared IP reputation — Another user on your shared hosting sent spam
• Missing authentication — No SPF, DKIM, or DMARC records
• Purchased email lists — Sending to addresses that didn't opt in

How to Check Blacklist Status

Check Your IP

Use our IP Sentry tool or check these resources:

• Query multiple blacklists at once with aggregate checkers
• Check both your server IP and any outbound SMTP relay IPs
• Also check IPv6 addresses if you send over IPv6

Check Your Domain

Domain-based blacklists (DBLs) list domains rather than IPs:

# Check domain against Spamhaus DBL
dig yourdomain.com.dbl.spamhaus.org

# NXDOMAIN = not listed
# Any other response = listed

Major Blacklists

Blacklist	Type	Impact	Auto-Removal
Spamhaus SBL	IP	Very High	No
Spamhaus XBL	IP	Very High	Yes (after cleanup)
Spamhaus DBL	Domain	Very High	No
Barracuda	IP	High	No
SpamCop	IP	Medium	Yes (24-48 hours)
SORBS	IP	Medium	Some lists
URIBL	Domain	Medium	No

Requesting Removal

Spamhaus

1. Identify the specific list (SBL, XBL, PBL, DBL)
2. Fix the underlying issue
3. Visit the Spamhaus lookup page and follow removal instructions
4. XBL listings often auto-remove once the infected system is cleaned

Barracuda Central

1. Visit the Barracuda Reputation lookup
2. Enter your IP address
3. If listed, click the removal request link
4. Fill out the form explaining the issue and remediation

SpamCop

SpamCop listings are temporary and auto-expire within 24-48 hours if no new spam is reported. If you keep getting relisted, you have an ongoing spam problem to address.

Microsoft/Outlook

Microsoft maintains their own internal blocklist:

1. Visit the Microsoft Sender Support page
2. Use their delisting portal
3. Verify domain ownership
4. Request review

Google/Gmail

Google doesn't maintain a public blacklist, but they may block senders. To address:

1. Ensure proper authentication (SPF, DKIM, DMARC)
2. Use Google Postmaster Tools to monitor reputation
3. Reduce complaint rates and bounce rates

Preventing Future Listings

Technical Measures

• Implement SPF, DKIM, and DMARC — Proper email authentication
• Use dedicated IP — Don't share IP reputation with others
• Set up reverse DNS — Ensure PTR record matches your mail server hostname
• Monitor server security — Keep software updated, use strong passwords
• Rate limit outbound email — Prevent abuse if compromised

List Hygiene

• Use double opt-in — Verify subscribers want your email
• Remove bounces immediately — Don't retry invalid addresses
• Process unsubscribes promptly — Honor requests within 24 hours
• Re-engage or remove inactive — Purge addresses that never engage

Monitoring

• Set up feedback loops — Get notified of spam complaints
• Monitor blacklist status regularly — Catch listings early
• Track deliverability metrics — Bounce rates, open rates, complaints