I've got [DavMail](http://davmail.sourceforge.net/) running in Linux Mint so Thunderbird can access IMAP/SMTP/LDAP/CalDav. I've got everything working at this point except LDAP. Basically I can't figure out what the base DN should be. Where on my Windows XP box can I find this? I've tried a few things, and the address book always shows up blank once I add the LDAP server.
['https://superuser.com/questions/321083', 'https://superuser.com', 'https://superuser.com/users/75269/']
The "Base DN" when adding a new LDAP directory in Thunderbird should be `ou=people` as specified on [this page](http://davmail.sourceforge.net/thunderbirddirectorysetup.html) [davmail.sourceforge.net].

Contrary to what the screenshot in those instructions shows (in French, no less), your "Bind DN" should might actually be **your email address**. At least this was the case for me, with the educational ("Live@edu") version of Office365.

Also, not sure if this is worth mentioning, but I did have a really annoying problem with Thunderbird on Mac OS X which caused me to think that the LDAP lookup wasn't working at all: the dialog box which prompted for the password (to access the DavMail server) got stuck **under** a bunch of other windows, **and** on the wrong virtual desktop (I believe Apple calls these "Spaces"). Once I "discovered" the password prompt and gave it my OWA password, LDAP lookups in the addressbook with Shift + ⌘ + F worked just fine.
The `base object` for searches is something that your directory server administrator tells you. It might be possible to discover the `namingContext` of the directory server if you know the hostname and port upon which the server listens by querying the root DSE. See *[The root DSE](http://bit.ly/osZXFG)* for more information. 

The information regarding the `namingContext` might be protected by access control, in which case you must get the name of the `base object` from the directory server administrator. The directory server might master or shadow multiple naming contexts, in which case you must get the name of the `base object` from the directory server administrator.