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What is blacklisting
A blacklist is a list of IP addresses or other entities that are denied access to a particular service or area. Within Leaseweb, the terms blacklist and blacklisting primarily refer to email blacklists. Blacklisting simply means that an IP address has been added to one or more blacklists.
If you send email from a blacklisted IP address, your messages may not reach the recipient or may be delivered to the recipient’s spam folder instead.
IP addresses may also appear on greylists. Unlike blacklists, greylists temporarily delay or block email until an additional verification step has been completed. In practice, IP addresses used for email traffic are often greylisted when no reverse DNS (rDNS) record has been configured.
The opposite of a blacklist is a whitelist. When a whitelist is used, access is denied by default and granted only to the entities explicitly included on the whitelist.
Tips to avoid getting blacklisted
Beyond monitoring email content and volume, proper server configuration is essential to maintain a healthy sender reputation:
- Only send email to recipients who have explicitly subscribed via double opt-in
- Always include a valid unsubscribe link
- Avoid using single opt-in mailing lists, as they are prohibited under many anti-spam regulations
For more information, please refer to our Spam policy.
You can also reduce the likelihood of blacklisting by configuring the appropriate DNS records: creating additional DNS records decreases the chance of ending up on a blacklist. The following DNS records can help avoid blacklists:
In addition to email-sending behavior, an IP address may be blacklisted for other reasons, including:
- Being part of a dirty IP range
- Running an open proxy
- Having a generic rDNS record
- Hosting an infected server that is abused by a spam bot
- Hosting a TOR exit node
Are you blacklisted?
Several online tools allow you to check whether your IP address is listed on one or more blacklists.
Two commonly used blacklist lookup tools are:
- MxToolbox
- Checks your IP address against many major and minor email blacklists. If your IP address is listed, the result appears in red. Selecting the listing opens the blacklist provider’s website, where you can find additional information and delisting instructions.
- BlacklistAlert
- Checks whether your IP address is listed. Any listings are shown in red, and when available, a link to the blacklist provider is included.
How did I get blacklisted?
An IP address can be blacklisted for various reasons and by multiple providers. If you receive abuse reports and do not resolve the underlying issue, your IP address may become blocked from accessing certain websites, accessing services in a specific country or region, or from sending email altogether.
How do I remove my IP address from a blacklist?
For most blacklists, you can request delisting yourself by following the blacklist provider’s delisting procedure.
If an entire IP range was affected, Leaseweb’s Compliance department will investigate the issue and work to resolve it. If only your individual IP address was blacklisted, you should contact the organization or website responsible for maintaining the blacklist directly.
The table below lists the most common blacklists and their delisting procedures.
| Blacklist | What to do |
|---|---|
| Barracuda | Look up reputation and request delisting |
| DroneBL | Look up reputation and request delisting |
| SPAMRATS | RATS-Dyna RATS-NoPtr RATS-Spam RATS-Auth |
| 0SPAM | Eliminate the source of the abuse, remove the culprit, create a 0spam account and request delisting |
| MIPSpace | Request delisting |
| Spamcop | Delisting occurs automatically after 24 hours without new reports |
| Spamhaus | Request delisting |
| Suomispam | Request delisting |
Microsoft Hotmail.com live.com outlook.com msn.com | To request delisting from Microsoft services, complete the following steps to request delisting: Secure your web server * If your IP address was blacklisted because email accounts were compromised and used to send spam, first identify and eliminate the source of the abuse by securing your mail server and, if applicable, your websites. Verify that your IP address is not listed elsewhere – Use a blacklist lookup tool such as MxToolbox to check your server’s IP address against over 100 DNS-based email blacklists. – If your IP address is listed elsewhere, follow the delisting instructions provided by the blacklist operator before proceeding. Set a SPF record – Microsoft may reject email sent from IP addresses that are not authorized in the sender’s DNS records. – An SPF record is a TXT record that specifies which hosts are authorized to send email on behalf of your domain. – For more information, see our article on DNS record types. Set up a PTR record – Microsoft generally does not accept email from IP addresses that do not have a properly configured PTR (reverse DNS) record. You can configure your PTR record in the Customer Portal. – For more information, see our article on PTR records and Reverse DNS. Verify your mail server configuration – Use the MxToolbox diagnostics tool to verify that your server configuration is correct. If any checks fail, follow the recommended remediation steps. Request delisting – After completing the previous steps, request delisting using Microsoft’s Sender Information Form. |
Information
Please note that the Compliance Department is unable to assist with Microsoft delisting requests unless Microsoft has specifically instructed you to do so. If Microsoft has requested this, please contact us at abusedesk@global.leaseweb.com and include their email in your request.
Warning
Never request delisting before resolving the underlying cause of the blacklist. Make sure the root cause of the malicious activity was eliminated before submitting a delisting request.
Repeated delisting requests without resolving the underlying issue make future delisting requests increasingly difficult.
