I've seen in the Zimbra configs where one can specify a recurring password expiration value for users but since most of my users login via IMAP/POP I'd like to have it where they get an email at tiered stages before it actually does. Right now I use a postfix based mail system and we utilize a perl script to notify 14 days, 7 days and 1 day prior to the change requirement.

Has anyone done this before to the point that they have code they could "lend"?