security/smtpscan 0.5p1 OpenBSD

smtpscan is a remote SMTP server version detector. It can be used to guess which mail software is used on a remote server, that may hide its SMTP banner.

smtpscan works by testing the remote SMTP server reaction, thanks to tests defined in the tests (${PREFIX}/share/smtpscan/tests) file. Almost all of those tests consists in weird SMTP request, whose answer is not precisely defined in the corresponding RFCs. Some other times, they check whether the remote SMTP server is simply RFC compliant. After each test, remote server returns a SMTP Error Message. Fingerprints are made of SMTP Error Messages corresponding to the tests.