Automatically detects and blocks open mail relays
'Smtpblock' parses a *nix mail log. When new mail messages are detected, it performs DNSBL/SMTP relay tests. If the host is listed in a DNSBL or relays third-party mail, Smtpblock creates a firewall rule to block access to the localhost's SMTP port and/or creates a hash that can be referenced by sendmail's RFC-822 pattern matching feature. It keeps track of each host's test status and time when it will need to be rechecked, reducing the need to constantly check every host sending mail to the local system. Smtpblock can be run as a daemon continuously checking the mail log or as a standalone program parsing the entire log file. Hosts can be manually checked, blocked, or unblocked from the command line.
DocumentationUser manpage available in HTML format from http://web.archive.org/web/20050914060146/http://www.angmar.com/smtpblock/smtpblock_2.8_man_page.html
released on 26 December 2002
|License||Verified by||Verified on||Notes|
|BSD 3Clause||Janet Casey||22 August 2002|
Leaders and contributors
Resources and communication
|Required to use||sendmail|
|Required to use||Net_Netmask|
|Required to use||Perl 5.002 or later|
|Required to use||NMAP|
This entry (in part or in whole) was last reviewed on 1 March 2017.
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