SORBS Blacklist (2025): Why Your IP Is Listed & How to Remove It

When your emails stop landing in inboxes,  it’s most likely that your IP is listed on a blacklist like SORBS.

If you ignore it, your messages may keep bouncing, your domain reputation can drop, and your outreach might completely stall.

That’s why it’s important to check that you’re not on a blacklist. And if you are, fix what caused it and make sure it doesn’t happen again. 

In this guide, I’ll walk you through how to check if you’re listed, what triggered it, and how to remove your IP the right way, so your emails start landing again.

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Key Takeaways

• The SORBS blacklist flags IPs for open relays, spam-like behavior, insecure proxies, or DNS misconfigurations.
  
  
• Each zone in SORBS represents a specific issue, identifying the right one helps fix and delist faster.
  
  
• Delisting involves fixing the root cause, testing your setup, and submitting a removal request for the affected zone.
  
  
• A correct DNS setup with SPF, DKIM, DMARC, PTR, MX, and A records is essential to prevent re-listing.
  
  
• Consistent sending patterns, verified lists, and regular IP monitoring keep your reputation stable.
  
  
• Warmforge makes it easier by handling DNS alignment, mailbox warmup, and blacklist monitoring automatically.

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Protect your domain reputation and keep your IP off blacklists. Start with Warmforge today.

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What Is the SORBS Blacklist?

The SORBS Blacklist (Spam and Open Relay Blocking System) is a DNS-based spam blocking service.

It works by scanning emails sent through open relays and proxies and adding those IP addresses to a blacklist.

SORBS lists IPs from botnets, infected machines, dynamic IP space, spammers, hijacked or hacked servers, honeypots, and spamtraps.

It also provides tools for a SORBS Blacklist check, open relay testing, proxy checking, and real-time IP lookups.

The system is run by volunteers and works through donations of money, hardware, software, or time.

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Might be helpful for you: How Blacklisted IPs Impact Email Deliverability

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How SORBS Works?

Here’s a simple look at how the SORBS system operates and what happens behind the scenes when an IP gets black listed.

1. It starts by collecting data from different sources

SORBS gathers information from honeypots, spamtraps, open relay and proxy scans, and reports from system administrators.
All this helps it detect servers that send spam or aren’t properly secured.

2. Each problem is placed into its own zone

Every issue is grouped into a specific DNS zone.
Each zone represents a reason for blacklisting, like open relays, proxies, dynamic IPs, or recent spam activity.

3. The listed IPs are added to a public database

Once an issue is confirmed, the IP is added to the right blacklist zone.
Each entry shows why it’s listed, helping administrators see what needs fixing.

4. Useful tools help with testing and checks

SORBS provides real-time IP lookups, open relay and proxy tests, and data on zombie networks and vulnerabilities, so admins can verify and secure their systems easily.

5. Mail servers use the list before delivering emails

Mail systems check these lists before accepting a message.
If the sender’s IP appears on the blacklist, the email is often rejected or flagged as spam.

6. The whole system runs through community support

SORBS operates through volunteers and donations, cash, hardware, or software.
When DDoS attacks happen, larger networks help share the load and keep things running smoothly.

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SORBS Blacklisting Criteria (Why Someone Gets Listed)

If your IP has been added to the SORBS blacklist, it usually means your email setup is doing something that looks risky or spam-like.

Here’s what most often causes it.

1. Letting anyone send emails through your server

This happens when the mail server allows sending without any login or control.
Spammers find such open servers and use them to send thousands of emails.
When SORBS detects that, it lists the IP to stop it.

2. Leaving your proxy open for public access

If a proxy (like HTTP or SOCKS) is open for anyone to connect, spammers can route their traffic through it.When that happens, it looks like the spam is coming from your network.

SORBS flags the IP immediately to prevent abuse.

3. Sending emails that reach SORBS spam traps

SORBS uses hidden email addresses called honeypots to catch spam.
When your messages land there, it means something’s off, maybe old contacts or unverified lists.

That’s enough for SORBS to add your IP to the list.

4. Sending mail from a home or dynamic internet connection

This happens when your mail system runs on a home or changing IP.
These IPs aren’t meant for sending mail and can be used by many people over time.
SORBS lists them automatically to avoid spam from unstable sources.

5. Having a hacked or infected server

If your system has malware, a botnet takes over your system quietly. It might start sending spam without anyone noticing.
SORBS lists such IPs until the system is fixed and secure again.

6. Using wrong or missing DNS records

When DNS records like A, MX, or PTR are missing or broken, your setup looks suspicious. Even if emails are real, SORBS flags those IPs until the DNS setup is corrected.

7. Being on a network that ignores spam

If your hosting provider doesn’t fix spam complaints, SORBS may block the whole network to protect others, even if clean senders get affected.

Each of these reasons puts your IP in a specific DNSBL zone, and that zone decides what needs to be fixed before delisting.

Prevent blacklisting before it starts, keep your domains aligned and safe with Warmforge.

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How to Check If You’re Listed on SORBS

SORBS isn’t active anymore, but old SORBS data can still sit in spam filters or cached blocklists that were never updated.

So, it’s still helpful to check whether your IP was ever listed and may be affecting your inbox placement today.

You can easily find out if your IP or domain is on the SORBS blacklist by following these quick steps.

1. Try loading the old SORBS lookup page

The original lookup sometimes loads with cached results.

• Visit dnsbl.sorbs.net
  
  
• Enter your IP or domain
  
  
• See if any old listing appears
  

If the site doesn’t load, that’s normal, but a quick check doesn’t hurt.

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2. Use a multi-blacklist checker that still displays legacy SORBS data

Some free DNSBL checkers still show whether your IP has ever had a SORBS entry stored in their system.

You can use any general blacklist scanner, such as:

• MXToolbox

• DNSBL.info
  
  
• Multirbl.valli.org
  

These won’t show new SORBS listings (because SORBS is offline), but they can show old cached records if your IP was previously listed.

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3. Look at inbox behaviour

Your inbox results often tell you more than any blacklist tool.

Watch for:

• Sudden spam-folder placement
  
  
• Reduced inboxing in Gmail or Outlook
  
  
• “Unverified sender” warnings
  
  
• Sudden drops in open rate
  
  
• New bounce codes pointing to reputation issues
  

Any of these signs can hint that a past SORBS listing, or something very similar to it, is still affecting your reputation.

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4. Run a basic deliverability or DNS health check

A quick DNS check helps you see:

• If SPF is valid
  
  
• If DKIM is signing
  
  
• If DMARC is aligned
  
  
• If your domain looks safe to inbox filters
  

You can use Salesforge’s free SPF Checker and DKIM Checker to check it instantly.

Both tools show you if anything in your DNS could still trigger SORBS-style filtering.

One simple idea to keep in mind

You don’t need SORBS to be online to know if an old SORBS-style signal is hurting you.
Modern filters still respond to the same issues SORBS used to flag, so a quick reputation check tells you everything you need.

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What To Do If You Were Listed on SORBS (Since You Can’t Delist Anymore)

SORBS is shut down, so there’s no delisting form or support team anymore.
The only thing that matters now is fixing anything in your setup that inbox providers might still treat as a “SORBS-style” red flag.

Here’s the simplest way to do that.

1. Secure your mail server

Make sure no one can send email through your server without permission.
Just do these basics:

• Require login for sending
  
  
• Disable any public or anonymous sending options
  
  
• Restrict access to trusted users only
  

This instantly removes the biggest risk that hurts your reputation.

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2. Lock down any open access points

If your server or site has anything publicly accessible, close it or secure it.
This includes:

• Open proxies
  
  
• Old or vulnerable form scripts
  
  
• Unused ports
  
  
• Anything publicly reachable that isn’t needed
  

A closed, secured server looks much safer to inbox filters.

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3. Clean and update your systems

Make sure your server is healthy and not being misused by anything in the background.
Simply:

• Update software
  
  
• Remove outdated scripts
  
  
• Scan for malware
  
  
• Reboot with clean configurations if needed
  

A clean system rebuilds trust over time.

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4. Fix and align your DNS settings

Your DNS tells inboxes whether your emails are legitimate.
Make sure these are correct and valid:

• SPF → must list your sending server
  
  
• DKIM → must be active and signing mail
  
  
• DMARC → should enforce SPF + DKIM alignment
  
  
• PTR → your IP should resolve back to your domain
  
  
• MX → correct mail routing
  
  
• A record → domain should map to the right IP
  

If these are aligned, most reputation issues start improving on their own.

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5. Warm your sending reputation slowly

Restarting too aggressively can trigger new filters.
Keep it simple:

• Send a small amount first
  
  
• Increase gradually
  
  
• Spread sending across mailboxes if possible
  
  

A slow warmup shows inbox providers that your sending is stable and safe.

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6. Check active blacklists (not SORBS)

Make sure you’re clean on modern lists inbox providers still use:

• Spamhaus
  
  
• Barracuda
  
  
• UCEPROTECT
  
  
• Invaluement
  

This helps you avoid new blocks while repairing old reputation signals.

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7. Use a tool that keeps everything aligned

Warmforge helps with the parts that matter most today by:

• Fixing DNS alignment
  
  
• Warming mailboxes gradually
  
  
• Monitoring active blacklists
  
  
• Sending alerts if anything starts hurting the reputation
  

It keeps your setup stable so you don’t run into legacy blacklist issues again.

Key point:

You can’t remove a SORBS listing anymore.
But you can fix the setup issues that still affect your inbox placement today.

Related reads: What Are Email Blacklists and How to Avoid Them

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Understand SORBS DNSBL Zones So You Can Fix the Right Problem

When an IP gets listed on SORBS, it’s not always for the same reason.
SORBS uses 17 different DNSBL zones, and each one represents a different issue: open relays, proxies, spam traps, or even infected servers.

Knowing which zone you’re listed in helps you fix the exact problem instead of guessing or trying random solutions.

Below is a simple breakdown of every zone and what it means, so you can find out why you’re listed and how to get it resolved.

How This Helps You

When you know the zone name, you know the root cause.
Each one points directly to what needs fixing, whether it’s DNS, open relays, malware, or sending behavior.

Once you match the zone to the issue, you can fix it once and delist faster without trial and error.

DNS Zone Configuration Checklist (Critical for Clean Sending)

A clean DNS setup is the foundation of safe email sending.
Even one wrong or missing record can make your IP look risky and get you blacklisted on systems like SORBS.

Here’s what to double-check:

✅ SPF Record – Defines which servers are allowed to send for your domain.
✅ DKIM Record – Adds a digital signature to prove your message is real.
✅ DMARC Policy – Aligns SPF/DKIM and reports misuse or spoofing.
✅ Reverse DNS (PTR) – Must point your IP back to your domain name.
✅ MX Records – Direct incoming mail to the right mail server.
✅ A Records – Map your domain correctly to its IP address.

Even small DNS mismatches can make you look like a spam source, something SORBS-style filters instantly detect.

💡 Pro tip:
If you don’t want to handle DNS alignment manually, Infraforge takes care of it for you.
It sets up SPF, DKIM, DMARC, and PTR automatically, so every domain you send stays authenticated, trusted, and protected from blacklists.

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How to Prevent Getting Blacklisted Again

Once your IP is off the SORBS list, keeping it clean comes down to steady maintenance and proper setup.

Here’s what helps you stay safe long-term:

• ✅ Keep your DNS records aligned
  
  
  • Always verify SPF, DKIM, DMARC, and PTR records.
    
    
  • Even a small mismatch can make your domain look untrustworthy.
    
    
  • Use Warmforge; it automatically validates these records and keeps them aligned, so you never get flagged for DNS errors again.
    

• ✅ Secure your mail server
  
  
  • Close any open relays or anonymous sending options.
    
    
  • Require authentication for every outbound email.
    

• ✅ Monitor your IP health
  
  
  • Check your IP status on SORBS and other DNSBLs regularly.
    
    
  • Catch and fix small issues before they cause delivery problems.
    

• ✅ Send only to clean, verified lists
  
  
  • Avoid purchased or outdated lists; they often contain spam traps.
    
    
  • Make sure everyone you email has opted in.
    

• ✅ Keep your sending pattern natural
  
  
  • Don’t send large batches suddenly.
    
    
  • Warm up new IPs gradually and keep volume steady.
    

• ✅ Update and secure your systems
  
  
  • Patch servers, scripts, and plugins often.
    
    
  • Prevent hackers or bots from using your system for spam.
    

• ✅ Use reliable sending infrastructure
  
  
  • Avoid shared or spam-tolerant networks.
    
    
  • Stick with trusted, managed sending environments built for deliverability.
    

Staying off the SORBS blacklist isn’t a one-time fix, it’s a routine.
With Warmforge, you can automate that routine, keeping your domains warmed, verified, and safe from future blacklisting.

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Stay Off the SORBS Blacklist with Warmforge

Warmforge is a Cold Email Warmup platform that keeps your domains, IPs, and mailboxes clean, warmed, and trusted, so you never get blacklisted again.

Fixing a listing is one thing, but maintaining a healthy reputation long-term is where Warmforge truly stands out.

Here’s how Warmforge helps:

• Automated SPF, DKIM, and DMARC setup
  Automatically sets up and aligns your authentication records, no manual DNS edits needed.
  
  
• Smart mailbox warmup and IP rotation
  Gradually builds sending reputation while rotating mailboxes to distribute volume safely.
  
  
• Blacklist & reputation monitoring
  Tracks your IPs and domains across SORBS, Spamhaus, Barracuda, and other major blacklists in real time.
  
  
• AI-based sending behavior
  Adapts your sending speed and frequency to avoid spamtraps and sudden spikes that trigger filters.
  
  
• Real-time alerts
  Sends instant notifications before your domain reputation drops, so you can fix issues early.
  
  

With Warmforge, your emails stay trusted, your domains stay protected, and your IPs never end up back on blacklists like SORBS.

Conclusion 

Getting delisted from SORBS is a must, but what matters more is keeping your sender reputation clean every day.
That mostly comes down to steady DNS alignment, safe sending habits, and a bit of regular monitoring.

Warmforge handles the technical setup, keeps your records aligned, warms your mailboxes safely, and alerts you before small issues turn into blacklists.

With the right setup and a little help from tools that keep things steady, your emails stay trusted, and your IPs stay clean. 

Protect your domain reputation and stay off blacklists with Warmforge.

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FAQs

1. What is the SORBS blacklist?

It’s a database of IPs and domains flagged for spam-like behavior, like open relays, bad DNS, or infected servers.
If you’re listed, many mail servers may block or filter your emails.

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2. How long does it take to get delisted from SORBS?

 It depends on the reason.
Simple issues can be cleared in a few days.
Repeat or network-wide listings can take longer, sometimes needing manual verification or donations for removal.

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3. Is SORBS still active in 2025?

No. SORBS has been officially shut down.
But its system and rules still influence how many spam filters work today.

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4. Can a SORBS listing affect Gmail or Outlook?

Yes, indirectly.
Even if Gmail or Outlook don’t use SORBS directly, being listed can hurt your sender reputation and inbox placement.

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5. Why did I get listed when I wasn’t sending spam?

It can happen if your IP was part of a shared network, had open ports, bad DNS records, or outdated mail scripts that spammers exploited.

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6. How can I avoid getting listed again?

Keep DNS records (SPF, DKIM, DMARC, PTR) aligned.
Send only to verified contacts.
Monitor your IP health regularly and keep your server secure and updated.

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7. Does Warmforge help if I’m already blacklisted?

Yes.
Warmforge helps fix DNS alignment, warm your mailboxes, and monitor blacklist status, rebuilding your sender reputation safely.

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