When enabled, the CardDAV module allows Cyrus to function as a contacts server. This module uses a subset of the mailbox hierarchy as addressbook collections, the toplevel of which is specified by the addressbookprefix option. The public addressbook hierarchy will reside at the toplevel of the shared mailbox namespace. A user's personal addressbook hierarchy will be a child of their Inbox.

For example, using the default value for addressbookprefix, an addressbook named Default for user "murch" would reside in the mailbox named user.murch.#addressbooks.Default.


Note that mailboxes in the addressbook hierarchies (those under addressbookprefix) should not be accessed with an IMAP client as doing so will leave a mailbox in a state unsuitable for CardDAV. To this end, addressbook mailboxes will not returned by Cyrus imapd in response to an IMAP client's request for the available mailbox list, but Cyrus imapd can not otherwise prevent an IMAP client from accessing them.


The CardDAV module will automatically create a default addressbook for a user the first time that the user authenticates to the CardDAV server. Note that the user MUST have an existing IMAP Inbox in order for the addressbook to be created.

There is also a Cyrus web GUI for managing addressbook resources. It allows you to:

  • Create new collections

  • Delete existing collections

  • Download existing collections via prepared URLs

The Cyrus web GUI for addressbook management is disabled by default, but can be enabled with the "carddav_allowaddressbookadmin" option.

To access the Cyrus web GUI for addressbook management, point a web browser at https://<servername>/dav/addressbooks/user/<username>

Addressbook access controls

Cyrus uses the same access controls for addressbooks as it does for calendars, except that the scheduling rights (7, 8, 9) have no use with addressbooks and are ignored.