We need an Atmail plugin for allowing users to change password options against a custom mail-server backend (qmail + vpopmail).
Atmail WebClient Evaluation is available here: [login to view URL]
Atmail demo is available on Atmail website [login to view URL]
Documentation on writing a plugin for Atmail is also available here http://support.atmail.com/display/DOCS/Creating+Plugins.
Vpopmail website: [login to view URL]
Vpopmail API: [login to view URL]