no, but the linked product (mail-in-a-box) uses ownCloud's webDAV/calDAV implementation rather than providing a separate means. in my experience if ownCloud is

no, but the linked product (mail-in-a-box) uses ownCloud's webDAV/calDAV implementation rather than providing a separate means. in my experience if ownCloud is supplied with a self-signed cert, the webDAV module throw errors but still works correctly. It's really obnoxious and causes a nag-window at the top of the main settings UI until either you comment out the nag window or buy a signed cert.