When enabled, the WebDAV module allows Cyrus to function as a storage server. This module uses a subset of the mailbox hierarchy as collections, the toplevel of which is specified by the davdriveprefix option. The public storage hierarchy lives at the toplevel of the shared mailbox namespace. A user’s personal storage hierarchy will be a child of their Inbox.

For example, using the default value for davdriveprefix, an collection named photos for user “murch” would reside in the mailbox named user.murch.#drive.photos. A user would access their storage at https://<servername>/dav/<davdriveprefix>/user/<userid>, which for the example above, comes to: https://<servername>/dav/drive/user/murch.


Note that mailboxes in the storage hierarchies (those under davdriveprefix) should not be accessed with an IMAP client as doing so will leave a mailbox in a state unsuitable for WebDAV. To this end, storage 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 WebDAV module will automatically create a toplevel (root) collection for a user the first time that the user authenticates to the WebDAV server. Note that the user MUST have an existing IMAP Inbox in order for the root collection to be created.

Storage access controls

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