DavMail Directory support is now available to access Exchange address book through LDAP.
Open Thunderbird address book and choose File/New/LDAP Directory:
Choose a name, host is always localhost, LDAP base context ou=people, adjust port to your settings and set user to your Active Directory account name, i.e. domain\account. Leave other options to default values.
You may also want to use this directory for mail completion in compose window :
Proceed to Thunderbird Carddav setup