This extension is EXPERIMENTAL. The behaviour of this extension -- including the names of its functions and anything else documented about this extension -- may change without notice in a future release of PHP. Use this extension at your own risk.
This extension has been moved from PHP as of PHP 4.3.0 and now vpopmail lives in PECL.
As of PHP 4, these functions are only available if PHP was configured with --with-vpopmail[=DIR].