Just a list of items we have seen and used for password expiration notifications:

• Novell Password Expiration Notification Job
  • Novell Jobs

• Lothar Haeger's Password Expiration Notification Driver
  • Password Notification Service Driver

• Novell IS&T Password Expiration Email Notification

• Password-Expiration and Grace-Remaining Email Notify (PERL Script)

• OpenAdaptor and Password Expiration Notification

• LDAP expired password notification (AppleScript)