This plugin provides Squirrelmail with the functionality of Access Control Lists (ACLs) aka Permissions per User, that is available in many modern IMAP servers, the most popular open-source one being Cyrus IMAP.
ACLs allow you to declare such things as:
...et cetera.
The user that you allow the those rights to, will see your folder INBOX.foo, assuming your username is foobar, as "user.foobar.foo", in normal namespace, or "Other Users.foobar.foo" in Alternate Namespace.
The only requirement is an IMAP server that supports the IMAP ACL extension.
The only tested IMAP server at the moment is Cyrus IMAP.
This plugin has been based on some of the functionality - and code - of the Cyrusmaster project.
Main Plugin Code: Alexandros Vellis
Some GUI code and backend classes (IMAP ACLs) originally written by:
The email.uoa.gr project (an LDAP-enabled, scalable and feature-rich mail system).