I think I've worked out what I've been doing wrong, but it's a longish story...
Forgive me if most of this is well-known, but it's taken me a while to put it together - mostly because things I did have muddied the waters and I couldn't see where I'd gone wrong. AddressBook.app on the Mac allows you to do a CardDAV connection to address books on the SOGo server. Great. So you fire up iCal and enter a name in your event invitee list and the search returns nothing. iCal can't find contacts in a CardDAV address book configured in AddressBook.app. Where things get confusing (and I was confused!) is that iCal seems to cache some contacts so it might find some people from your cache that you also know are in your CardDAV address book, so you think it's partially working. Bummer. Undaunted, you use Directory Manager and add details of your LDAP server as a Contacts lookup. You notice that iCal looks for a few special Apple LDAP attributes so you add them to your LDAP and all of a sudden, lookups work in iCal. But free-busy lookups don't work. It turns out this is because iCal does a second request to your LDAP asking for a whole lot of other special Apple attributes that you don't have (and never will) so free-busy fails. The end result is that free-busy does work against the SOGo server, but only for contacts that iCal can find in the "On My Mac" section of the AddressBook.app address books. Cheers, Bill -- users@sogo.nu https://inverse.ca/sogo/lists
