Net::DNSBL::MultiDaemon is the Perl module that implements the multi_dnsbl
multi_dnsbl is a DNS emulator daemon that increases the efficacy of DNSBL
look-ups in a mail system. multi_dnsbl may be used as a stand-alone DNSBL or as
a plug-in for a standard BIND 9 installation. multi_dnsbl shares a common
configuration file format with the Mail::SpamCannibal sc_BLcheck.pl script so
that DNSBL's can be maintained in a common configuration file for an entire
Because DNSBL usefulness is dependent on the nature and source of spam sent to
a specific site and because sometimes DNSBL's may provide intermittant service,
multi_dnsbl interrogates them sorted in the order of greatest successful hits.
DNSBL's that do not respond within the configured timeout period are not
interrogated at all after 6 consecutive failures, and thereafter will be
retried not more often than once every hour until they come back online. This
eliminates the need to place DNSBL's in a particular order in your MTA's config
file or periodically monitor the DNSBL statistics and/or update the MTA config
MailScanner is a complete e-mail security system designed for use on
e-mail gateways. It protects against viruses, and detects attacks against
e-mail client packages (such as Outlook, Outlook Express, Eudora). It can
also detect almost all unsolicited commercial e-mail (spam) passing through
it and respond to all incidents in a wide variety of ways.
Not only can it scan for known viruses, but it can also protect against unknown
viruses hidden inside e-mail attachments by refusing entry to attachments whose
filenames match any given pattern. This can include generic patterns that trap
filenames attempting to hide the true filename extension (e.g. ".txt.vbs").
It is superior to many commercial packages in its ability to handle attacks
against itself, such as Denial Of Service attacks caused by messages containing
the "Zip of Death". It is easy to install into an existing e-mail gateway,
requiring very little knowledge of sendmail and no change to an existing
MailScanner itself is entirely open source, but it uses widely known commercial
virus scanning packages at its core. The other software it uses is all high
quality open source software, leading to a system that can be trusted for
performance and reliability.