The Ascams DNSBL Block List is an IP-based blocklist (or blacklist) that functions as a "DROP" list, identifying IPs involved in malicious activities like hacking, malware, and spam based on a detailed reputation scoring system.
The Ascams DNSBL Block List (dnsbl.ascams.com) is a specific type of IP-based blocklist. It functions as a DROP list, which means any system using it is advised to drop or completely block connections from listed IPs, rather than simply flagging them as potential spam.
This blacklist's policy is to list IP addresses that are actively involved in hacking, malware distribution, general abuse, and spam. It also includes non-managed IP ranges, hijacked ASNs, or dynamic IP ranges. All of these are considered unsafe to receive connections from.
Listings on this particular blocklist fall into two main categories, which is an important distinction to make if you find your IP on this list.
The Ascams DNSBL Block List is operated by Ascams, an organization run by an individual named Del. Ascams maintains a comprehensive reputation scoring system for a vast number of IPv4 addresses.
When a score is requested for an IP, Ascams cross-references it with other data providers to ensure the information is current. The score is calculated using various data points, including bounce messages, PTR records, SPF records, listings on other RBLs, reverse DNS information, and records of scam or malware activity. Members of the Ascams service can request manual re-evaluations and sometimes view the specific data contributing to an IP's score.
The removal process from the Ascams DNSBL Block List depends on whether your listing is temporary or permanent. As noted, temporary listings are removed automatically once the abusive traffic stops. For these, you do not need to do anything other than plug the leak.
For permanent listings, the delisting process is entirely manual and requires an investigation for each IP address. While removal is free for resources that qualify, it is known to be a challenging process. Removals can take anywhere from 7 to 30 days or longer; there are no instant delisting options.
Before you request removal, it is critical to investigate why you were listed and resolve the underlying issue. Ascams recommends asking yourself several questions:
If you are an Ascams member, you should log in to the member portal to submit support and removal requests.
If you are not a member, you must follow a strict checklist to apply for removal via email. Failure to comply will result in your request being discarded.
The success of your delisting request can also depend heavily on the reputation of the IP resource owner. If the owner has a very poor reputation score with Ascams, it may be impossible for a client or renter of the IP to get it delisted without the owner's direct involvement. Before paying for a new server, it is always a good idea to check the IP score first.
The impact of being on the Ascams DNSBL Block List is generally considered low. This blacklist (or blocklist) is not widely used by major mailbox providers like Gmail or Outlook.
However, it is a DROP list. This means any network administrator or mail server operator who does use this list will completely block and reject all connection attempts from your IP address. This can lead to your emails not being delivered to recipients on those specific networks. While the overall reach may be low, the impact can be absolute for the domains and servers that use this blacklist.
Organization
Zone
Type
Impact
Delisting
Organization
Zone
Type
Impact
Delisting
Organization
Zone
Type
Impact
Delisting
19 resources
What are examples of insignificant or ineffective email blocklists?
What caused the SpamCop domain to be listed and blocked in January 2021?
What common blocklists or services cause 'message rejected as spam' errors for ESPs?
Why am I seeing Spamhaus DBL block messages for IP address lookups?
Why is my AWS hostname blacklisted in Abusix and how do I resolve it?
Why is my IP repeatedly blocklisted by Spamhaus XBL?