Usually subscribe with "subscribe <listname>" in the body of a message to the listed Email address.

• Best of Security List (bos) - best-of-security-request@cyber.com.au
• Bugtraq Full Disclosure List (bugtrag) - listserv@netspace.org
• CERT Advisories (cert-advisory) - cert-advisory-request@cert.org
• CIAC Advisories (ciac-bulletin) - majordomo@tholia.llnl.gov
• COAST Security Archive (coast) - coast-request@cs.purdue.edu
• Firewalls Digest (firewall-digest) - majordomo@greatcircle.com
• Firewall Wizards (firewall-wizards) - majordomo@nfr.net
• Intrusion Detection Systems (ids) - majordomo@uow.edu.au
• Linux Security Issues (linux-security) - linux-security-request@redhat.com
• Legal Aspects of Computer Crime (lacc) - majordomo@suburbia.net
• NT Security Issues (ntsecurity) - majordomo@iss.net
• The RISKS Forum (risks) - majordomo@csl.sri.com
• WWW Security (www-security-new) - majordomo@nsmx.rutgers.edu
• The Virus Lists (virus-l) - listserv@lehigh.edu
• The Virus Lists (virus) - listserv@lehigh.edu