Why is Spamhaus blocking outgoing mail? I was replying to one of my customers and received a Spamhaus bounce back. My mail server IP [19x.1xx.60.84] is being blocked by Spamhaus. Please help!
That was a recent support request we received in our Server Support Services for web hosts.
Spamming activities can cause mail server IP addresses to be added to email blacklist databases like Spamhaus. And, most servers do not allow mail from such IPs in blacklists.
Today, we’ll see how our Support Engineers restore mail functionality after a Spamhaus IP block and take proactive measures to prevent such incidents in the future.
This article has been updated for 2026 to reflect current Spamhaus policies, modern email authentication standards, and the latest sender requirements from major mail providers.
Seeing a bounce message that mentions Spamhaus can be stressful.
Your customers stop receiving emails. Support tickets increase. Business communication slows down.
This usually means your server IP is listed on a Spamhaus blocklist. Receiving mail servers that use Spamhaus may reject messages from your IP.
Here’s what that means today and how to fix it properly.
What Is Spamhaus?
Spamhaus is an organization that tracks spam, malware activity, botnets, and policy violations. It maintains several DNS-based blocklists that mail servers use to filter incoming email.
If your IP appears on one of these lists, mail providers such as Gmail, Outlook, or Yahoo may reject your messages.
Which Spamhaus List Is Your IP On?
Not all listings are the same. The fix depends on the list type.
- SBL – Spamhaus Block List
Used for verified spam sources. Manual investigation is usually required. - XBL – Exploits Block List
Lists IPs infected with malware or botnet activity. Some entries expire automatically after cleanup. - PBL – Policy Block List
It lists IP ranges that should not send mail directly. Common for residential or dynamic IP ranges. - CSS – Composite Snowshoe
Targets low-reputation bulk senders distributing traffic across multiple IP addresses.
Check your IP status here: https://check.spamhaus.org/
Identifying the correct list is the first step.
Why Your Server Got Listed
Common causes in 2026 include:
- Compromised email accounts
- Weak passwords without multi-factor authentication
- Infected WordPress or other CMS installations
- Outdated plugins
- Open SMTP relay
- Scripts abusing PHP mail()
- High spam complaint rates
- Missing SPF, DKIM, or DMARC records
Google and Yahoo tightened sender requirements in 2024. Authentication is now mandatory for bulk senders.
How to Fix Spamhaus Outgoing Mail Block
Step 1. Check the Exact Listing Reason
Use the Spamhaus lookup tool and review the listing description carefully. It will state the issue and required action. Do not request delisting before resolving the root cause.
Step 2. Investigate Server Logs
Check:
- Mail logs
- SMTP authentication logs
- Web server logs
- Mail queue
Look for:
- Sudden spikes in outbound mail
- Unknown authenticated users
- Large batches of similar messages
Finding the source is critical. Removing the listing without fixing the cause leads to re-listing.
Step 3. Clean the Server
Actions usually include:
- Disable compromised accounts
- Reset all email passwords
- Enable multi-factor authentication
- Scan all websites using tools such as Maldet or commercial malware scanners
- Update CMS installations and plugins
- Remove suspicious cron jobs
- Disable unused mail scripts
If the infection is widespread, migration to a clean server may be safer.
Step 4. Verify Email Authentication
Modern email delivery depends heavily on authentication.
Ensure the following are correctly configured:
- SPF record allows your mail server IP
- DKIM signing is active and valid
- DMARC policy is published
- Reverse DNS matches the sending hostname
- HELO hostname is valid
- TLS is enabled for SMTP
Authentication failures often trigger reputation issues, even if spam is not obvious.
Step 5. Submit Delisting Request
After cleaning the server, request removal via the Spamhaus lookup page.
Some lists auto-expire after cleanup. Others require manual review.
Provide accurate information in the delisting form. Do not submit multiple requests.
Step 6. Avoid Quick IP Rotation
Switching to a new IP address can temporarily restore mail. It also resets the reputation to zero.
New IPs require a gradual warm-up. Large volumes sent immediately from a fresh IP may trigger new blocks.
Fixing the root issue remains the safest solution.
Preventive Measures to Avoid Future Listings
Prevention requires continuous monitoring.
- Monitor Outbound Mail Volume
Set alerts if the mail queue crosses a defined threshold. - Enforce Strong Authentication
Require complex passwords and multi-factor login for all email users. - Rate Limit SMTP
Limit the number of messages each user can send per hour. - Disable Direct PHP mail()
Force authenticated SMTP usage. - Monitor IP Reputation
Check regularly using Spamhaus lookup, MXToolbox, and Google Postmaster Tools. - Maintain Updated Software
Keep the OS, control panel, CMS, and plugins up to date.
Conclusion
Spamhaus listings usually result from compromised accounts or malware activity. Modern email systems also enforce strict authentication and reputation standards.
Continuous monitoring protects your IP reputation long term. Bobcares provides proactive Server management support to help prevent blacklisting and keep your mail services stable and secure.
Hello,
I use Surfshark VPN. However all my mails (private) are blocked by Spamhaus. How can I solve this issue?
Thank you in advance for your reaction.
Regards,
Jan ter Beek
Hello Jan,
For some reason, Spamhaus is blocking mails from your IP address. The fix involves figuring it out and then delisting. Our Engineers can help you. We’ll be happy to talk to you on chat (click on the icon at right-bottom).
The real problem is that Spamhaus block blocks not addresses. I am blocked because someone at 82.x.x.x has done something yet I am at 80.x.x.x They are completely irrational and obstructive. They get away from getting sued into obscurity because it is the little guy that suffers and they grandstand on the moral highground while not actually doing an effective job. Even the writer says his company have to get another IP address rather than expect them to actually do the job they are being paid for.
Hello Jamie,
Yes, Spamhaus block the server IP address even if a single user misuses the mail server. Replacing the mail server IP address works as a quick fix to minimize mail downtime.
hell im scared to even try anymore. its just away fot people to keep using me and planning there exit without my knowledge that ive been there songbird dropping notes off randomly
Hi chase,
Our experts can help you with the issue.we will be happy to talk to you through our live chat(click on the icon at right-bottom).
Hello,
I’ve had two emails returned to me today from MAILER-DAEMON@xxxx.com saying “Undelivered Mail Returned to Sender.” Oddly enough, the second email returned to me was in a chain of emails to someone – the first went through without any problems.
I don’t understand Spamhaus’s directions for getting my mail through. Can you help me? Thanks!!
Hello Barbara,
We need to check the email failure message to know the reason for the error. If you still have errors and need help, we’ll be happy to talk to you on chat (click on the icon at right-bottom).
This SpamHouse seems like a real pain in the butt.
Same problem here. My IP address were never ever used as a mail server and is simply blocked by those idiots.
Sent de-list request but they simply won’t do it. Now because I really need to start my own mail server I simply can not do it.
Self elected idiots telling us what we can and what we can not do. We pay for internet access not for being blocked by some idiots. I’m really pissed.
Hi,
Our experts can help you with the issue.we will be happy to talk to you through our live chat(click on the icon at right-bottom).
I was doing just fine till Spamhaus come along. Now it’s pure hell. Cannot count the number of times I’ve been forced into expending valuable time looking up a phone number to call someone all because I got spammed by Spamhaus. Go figure …..!!!
Recently I have received this message several times when sending out just 1 email: spamhaus.org/query/bl?ip=185.54.228.115 However, the message usually gets sent after about 60seconds.
My internet connection is mobile broadband so the IP changes with each log on but it goes through the server of my ISP.
I publish a newsletter monthly for a not-for-profit organisation, sending to around 460 members and have been brought up short by new spamming restrictions and can only send out 35 addresses at a time without getting pinged. This goes for gmail and my organisation’s domain name. Are these incidents related and what can I do to continue emailing the newsletter?
Thank you
Hi Andrea,
We need to check the email logs for a detailed understanding of the situation. If you still receive these messages while sending emails and need help, please initiate a chat from the icon at right-bottom. We’ll be happy to help you.
I am able to receive the messages from client’s end but unable to reply or send new messages and getting this message
xxx@xxx.com
host mx10.xxx.com [213.143.146.147]
SMTP error from remote mail server after pipelined MAIL FROM: SIZE=10258:
550 5.7.1 103.129.98.16 listed at zen.spamhaus.org
Hi there,
It looks like your IP address is blacklisted. You will need to figure out the reason why it got listed and submit a request at their end for delist. We are happy to help you. To contact our support team, please initiate a chat from the icon at right-bottom.
My Thunderbird app says that Spamhaus is blocking my IP. Is it because of using Tunnelbear? I’ve noticed the VPN causes some issues. Thanks, Karen
I need help with preventing my email from getting bounced back
Hi,
Please contact our support team via live chat
I am having trouble with spamhaus and my mail.com email account.
I need this as we are trying to conduct business but have no idea of where to start as it is way out of my league.
Hi,
Please contact our support team via live chat