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Unlisted
If your server IP is not found on the checked blacklists, it means that there is currently no corresponding entry there. That is a good starting point for the reputation of your mail server.
Important: Blacklists are only one part of email reputation. For actual deliverability, other factors such as SPF, DKIM, DMARC, sending behavior, server reputation, and evaluation by the receiving mail provider are also crucial.
Listed
Important: Blacklists are only one part of email reputation. For actual deliverability, other factors such as SPF, DKIM, DMARC, sending behavior, server reputation, and evaluation by the receiving mail provider are also crucial.
Identify causes
If attackers gain access to an email account's credentials, they can secretly abuse it to send large volumes of spam or phishing messages.
Malware on a server or end device can automatically send spam or perform other suspicious activities without the owner noticing immediately.
Security vulnerabilities in WordPress, plugins, or other web applications can allow attackers to use the server for unwanted mail delivery or other abusive activities.
A very high sending volume, many invalid recipients, spam complaints, or poorly maintained distribution lists can negatively impact the reputation of a mail server.
When multiple customers share the same outgoing server IP address, the abusive behavior of individual users can negatively impact the reputation of this shared IP address.
Insecure or faulty mail server configurations can facilitate abuse. For example, open mail relays or inadequately secured accesses are particularly critical.
A DNSBL (DNS-based Blacklist) or RBL (Real-Time Black List) is a database that records IP addresses associated with spam, malware, or other suspicious behavior.
Mail servers and security systems can take such lists into account when evaluating incoming emails. For this purpose, the IP address of the sending mail server is checked against one or more blacklists. If the address is listed, this can influence delivery depending on the recipient and the list used.
Fix blacklist entry
A blacklist entry should not simply be removed. First, it must be found out why the IP was listed. If a delisting is merely requested without eliminating the cause, the address can end up on a blacklist again.
Therefore, first check email accounts, websites, and servers for potential abuse. Only after spam sending, malware, compromised credentials, or other causes have been resolved should the delisting procedure for the respective blacklist be carried out.
Not every blacklist works the same way: The admission requirements, evaluation criteria, and delisting procedures vary depending on the operator. Therefore, always check the information of the specific list where your IP was found.
An IP blacklist is a list of IP addresses associated with spam, malware, abusive email sending, or other suspicious activities. Many of these lists are used as DNSBL (DNS-based Blackhole List) or RBL (Real-Time Block List) operated.
Mail servers and security systems can use this information as one of several signals to evaluate incoming emails.
Give the public IPv4 address of your mail server into the CURIAWEB blacklist checker field at the top of this page. The tool queries the supported DNSBLs and shows you whether an entry was currently found for the address there.
Currently SpamCop and PSBL Verified.
Common causes include compromised email accounts, spam distribution, malware, hacked websites, or insecure mail servers. Problematic mass mailing or the abuse of a shared server IP can also play a role.
That is why it is It is important to find the cause first and to eliminate before a delisting is applied for.
That is not necessarily the case. A blacklist entry can affect email delivery, but it is only one of several signals that receiving mail servers can use for evaluation.
What the actual impact of a listing is depends, among other things, on the specific blacklist, the receiving email provider, and other reputation and authentication features.
First, check why the IP address was listed. Inspect mail accounts, websites, and servers for compromised credentials, malware, spam sending, and other security issues.
Only when the cause has been resolved should you contact the operator of the blacklist in question request the planned delisting procedures. Otherwise, there is a risk that the IP will be listed again.
The procedure varies depending on the blacklist. Some operators automatically remove entries after the cause has been resolved, while others provide a dedicated delisting form or a corresponding process.
The CURIAWEB Blacklist Checker do not remove any entries. It merely indicates whether the checked lists report an entry for the entered IP.
No, SPF, DKIM, and DMARC are methods for email authentication or for defining and evaluating corresponding policies. A DNSBL or RBL, on the other hand, is a reputation or block list.
Faulty or missing email authentication can negatively impact deliverability. However, this does not automatically mean that an IP address is on a blacklist.
No. A result like „unlisted“ simply means that the IP was not found on the lists checked by the CURIAWEB blacklist checker.
For the actual Email delivery further factors play a role, including the reputation of the mail server, SPF, DKIM and DMARC, sending behavior, message content, and the evaluation by the receiving mail provider.
With a normally functioning mail server, occasional checks are useful. A blacklist check is particularly recommended if delivery suddenly deteriorates, emails are rejected, or unusual spam activities are detected.
For mission-critical mail servers, an automated Reputation and blacklist monitoring make sense.
Having problems with spam or email delivery?
Learn more about professional email security and SpamExperts at CURIAWEB.