Email security & antispam

Better than blacklists… EL is IP intelligence

Request Eval

Infographic: EL's pattern stays ahead of spammers vs DNSBLs that try to follow close behind spammers.

intelligence for reputation

First and foremost, EL is an effort to collect and classify all generic PTR / reverse DNS naming conventions currently in use, to aid in the evaluation of the risks of accepting mail from a given host. EL has many types of classification, including university residential networks, NAT/proxies, mass virtual web hosting services, and mail server farms.


This dataset is available for commercial use through a licensing agreement. As of this writing, there are over 125K patterns, covering over 48K domains worldwide. We license to blacklist operators, security research initiatives, antispam appliance vendors, reputation services companies, and social networks, and are working with antivirus vendors, ISPs and telcos, and enterprise infrastructure software companies.

in real time

Enemieslist data is made available via a custom DNSBL service, hosted on a patched rbldnsd, which uses a custom fast regular expression library and returns a variety of responses to DNS queries. This data is not currently available for public use, although we are exploring the possibility of making it available in the future. There is also a module with support for MessageSystems ecelerity. It may also be used via rbldnsd with Cloudmark Gateway.

Want to host a rbldnsd mirror?

open source software

Enemieslist is also an antispam package for sendmail, currently available via github, with experimental contributed versions for Postfix (in the form of several downloadable files and a policy daemon), Exim (in the form of several downloadable files), and qpsmtpd (in the form of a plugin, available in the public qpsmtpd svn repository), with an experimental version for SpamAssassin. All software made available is open source. Check out ways you can contribute.

For access to the rbldnsd patch, fast regex parsing library, and other tools, send us an email.


We host several mailing lists for the users of our software and data, as well as for discussion of antispam techniques and other relevant information. To request access to the latter, please contact the list owner.


Finally, Enemieslist is a blog where we post a wide variety of antispam and security related news items. It has an RSS feed for your convenience as well.