Is My Email Blacklisted? How to Check Your Domain

If your emails aren't being delivered, your domain might be blacklisted. Check your status right now:

A blacklisted domain can cause serious email delivery problems. But don't panic—most listings are resolvable. This guide explains how domain blacklisting works, how it differs from IP blacklisting, and what you can do about it.

Domain Blacklisting vs IP Blacklisting

When people ask "is my email blacklisted?" they usually mean their domain, but there are actually two types of blacklisting that affect email delivery:

Domain blacklisting targets your domain name (example.com). When your domain is blacklisted, emails from any address at that domain (@example.com, @mail.example.com) may be blocked regardless of which server or IP sends them. Domain blacklists like Spamhaus DBL, SURBL, and URIBL track domains used in spam.

IP blacklisting targets the server IP addresses that send your email. If your sending IP is blacklisted, emails from any domain sent through that IP are affected. IP blacklists like Spamhaus SBL, Barracuda, and Spamcop track IP addresses known to send spam.

Both types matter for deliverability. You might have a clean domain but blacklisted IP, or vice versa. Checking both gives you the complete picture.

Domain reputation has become increasingly important in recent years. As more email flows through shared infrastructure (cloud email services, hosting providers), domain-level signals have become more reliable indicators of sender legitimacy than IP-level signals.

Signs Your Domain Might Be Blacklisted

Email blacklisting often becomes apparent through delivery problems:

Sudden drop in deliverability: If your email open rates plummet or bounce rates spike, blacklisting might be the cause.

Bounce messages mentioning blacklists: Some rejection messages explicitly state that your domain or IP is listed on a specific blacklist. Check your bounce logs for these messages.

Recipients report not receiving your emails: When people expecting your messages say they never arrived, and the messages aren't in spam folders either, blacklisting could be blocking delivery entirely.

Emails consistently going to spam: If recipients always find your messages in their spam folder, your domain reputation may be damaged even if you're not formally blacklisted.

Delivery delays: Some servers don't reject blacklisted mail outright but queue it for additional scrutiny, causing delays.

These symptoms can have other causes (authentication failures, content issues, recipient-side filtering), but blacklisting is a common culprit worth checking.

Why Domains Get Blacklisted

Understanding the causes helps you fix the problem and prevent recurrence:

Spam complaints from recipients are the most common trigger. When people mark your emails as spam, this signals to blacklist operators that your domain sends unwanted mail. Even legitimate marketing emails generate complaints if recipients forgot they signed up or don't find the content valuable.

Spam trap hits are particularly damaging. Spam traps are email addresses that should never receive mail—either because they were never valid or because they were abandoned and later repurposed by anti-spam organizations. Sending to spam traps indicates poor list practices.

Domain appears in spam messages even when you didn't send them. Spammers sometimes include links to legitimate domains in their messages, causing those domains to get listed. This is called "domain reputation attack" and can affect innocent parties.

Compromised email accounts sending spam from your domain will quickly damage its reputation. A single hacked account can send thousands of spam messages before you notice.

Poor email authentication makes your domain easy to spoof. Without SPF, DKIM, and DMARC, spammers can forge emails appearing to come from your domain.

Purchased or scraped email lists contain invalid addresses and spam traps. Using these lists almost always results in blacklisting.

Sending patterns that look like spam: Sending huge volumes suddenly, emailing at unusual hours, or blasting to lists you haven't contacted in months can trigger blacklist additions.

Major Domain Blacklists

Not all blacklists track domains, but several important ones do:

Spamhaus DBL (Domain Block List) is the most influential domain blacklist. Spamhaus tracks domains found in spam messages, phishing attempts, and malware distribution. A DBL listing severely impacts deliverability.

SURBL (Spam URI Real-time Blocklists) tracks domains that appear in spam message bodies, particularly in URLs. It's designed to catch spam that links to specific domains.

URIBL serves a similar purpose to SURBL, tracking domains found in spam content.

Invaluement ivmSIP/24 tracks domains used in spam, primarily based on spam trap data.

SORBS includes some domain-based lists alongside its IP blacklists.

These domain blacklists are consulted by email servers worldwide. A listing on any of them can significantly hurt your email delivery.

What to Do If You're Blacklisted

If your domain appears on a blacklist, follow these steps:

Step 1: Identify All Listings

Check your domain against multiple blacklists to understand the full scope. Being listed on one blacklist often correlates with listings on others.

Step 2: Investigate the Cause

Before requesting removal, understand why you were listed:

• Review your sending logs for unusual activity
• Check for compromised accounts or unauthorized sending
• Examine your list sources and collection methods
• Look at spam complaint rates and bounce rates
• Verify email authentication is working properly

Step 3: Fix the Problem

Take corrective action based on what you find:

For spam complaints: Review your consent collection process. Make unsubscribing easier. Improve content relevance. Consider only emailing engaged subscribers.

For spam traps: Clean your list by removing addresses that haven't engaged in 6-12 months. Stop using any purchased lists. Implement double opt-in.

For compromised accounts: Reset all passwords, enable two-factor authentication, and audit account access. Scan for malware.

For authentication issues: Properly configure SPF, DKIM, and DMARC. Test that authentication is passing.

Step 4: Request Delisting

Each blacklist has its own removal process:

Spamhaus DBL: Visit their lookup page, search for your domain, and follow removal instructions. Spamhaus requires understanding and fixing the underlying problem.

SURBL: Use their removal form. They'll verify your domain is no longer appearing in spam before removing.

URIBL: Submit a removal request through their website.

Be honest and specific about what caused the listing and how you've addressed it. Blacklist operators have seen every excuse—straightforward explanations work better than elaborate denials.

Step 5: Monitor Your Status

After delisting, watch for recurrence. If you get listed again quickly, you haven't fully solved the problem. Continuous monitoring catches new listings before they cause widespread delivery failures.

Preventing Domain Blacklisting

Prevention is far easier than remediation:

Build your list properly using double opt-in confirmation. This ensures everyone on your list actually requested your emails.

Keep your list clean by removing bounces immediately, unsubscribing complainers, and periodically removing unengaged subscribers.

Authenticate your email with SPF, DKIM, and DMARC. This proves your legitimacy and prevents spoofing.

Make unsubscribing easy with clear, one-click unsubscribe links. People who can't easily leave your list will mark you as spam instead.

Secure your accounts with strong passwords and two-factor authentication. Monitor for unauthorized access or unusual sending.

Send relevant content that recipients want. High engagement (opens, clicks, replies) signals to providers that your email is wanted.

Monitor your reputation continuously. Don't wait for delivery problems to check your blacklist status.

When Your Domain Isn't Blacklisted But Email Still Fails

If your blacklist check comes back clean but emails still aren't delivering, other factors might be involved:

IP blacklisting: Your sending IP might be listed even if your domain isn't. Check your sending IPs separately.

Authentication failures: SPF, DKIM, or DMARC might be failing even without blacklisting. Check your authentication setup.

Content filtering: Spam filters look at message content, not just sender reputation. Certain phrases, formatting, or attachments trigger filtering.

Recipient-side blocking: Individual recipients or companies may have blocked your domain independently of public blacklists.

Reputation without formal listing: Your domain can have poor reputation at specific providers (Gmail, Microsoft) without appearing on public blacklists.

Check email authentication, review bounce messages for specific errors, and consider using tools like Google Postmaster Tools for provider-specific reputation data.

Monitor Your Blacklist Status

Checking once is good. Monitoring continuously is better. The Email Deliverability Suite checks major blacklists daily and alerts you if your domain or IP gets listed.