Changes

This special group is empty (no member), so this has limited impact on the security of the server. Just be sure to never add any user in this group. (It's a system group, and won't appear in the server-manager, so you cannot add members easily).

This special group is empty (no member), so this has limited impact on the security of the server. Just be sure to never add any user in this group. (It's a system group, and won't appear in the server-manager, so you cannot add members easily).

When a user access its mailbox through the IMAP server, dovecot spawn a new process with the standard user privileges, plus the sharedmailbox group. So basically a user is member of this special group only through dovecot. This configuration allows shared mailbox at the filesystem level. Effective permissions between differents users are enforced by IMAP ACL extension. You need a client which support this (tested with SOGo and Thunderbird using this extension ).

When a user access its mailbox through the IMAP server, dovecot spawn a new process with the standard user privileges, plus the sharedmailbox group. So basically a user is member of this special group only through dovecot. This configuration allows shared mailbox at the filesystem level. Effective permissions between differents users are enforced by IMAP ACL extension. You need a client which support this (tested with SOGo and Thunderbird using [https://addons.mozilla.org/fr/thunderbird/addon/imap-acl-extension/ this extension] ).

Once enabled, you can grant different access level (read, post, delete, change flags, create sub folders etc.) to other users, or group of users on your IMAP folders.

Once enabled, you can grant different access level (read, post, delete, change flags, create sub folders etc.) to other users, or group of users on your IMAP folders.