Using LDAP in Thunderbird 2.0 to query Microsoft Exchange for addresses

I've recently switched from Outlook to Thunderbird/Lightening for my email and calendaring needs. I use IMAP to talk to our Exchange server, but was missing being able to querying the global address book.

Thunderbird supports LDAP, but it took some digging around to get this to work right. Here's what I did.

1. In Thunderbird, I clicked "Go" and choose "Address Book"
2. I clicked "New" and "LDAP Directory"
3. In the "Directory Server Properties" window that appears, on the "General" tab I gave the "Name" a meaningful value (in this case, our Exchange server).
4. In the "Hostname" field I entered the FQDN of our Exchange server (i.e. mail.mycompany.com)
5. For Base DN, since I know we're not doing anything fancy I entered in "DC=mycompany,DC=com" since I know that's our AD root DN.
6. For "Port Number" enter 3268. I was a little confused at first as I could telnet to our Exchange server over both LDAP and LDAP/SSL ports. But, Thunderbird couldn't seem to query them. But after googling Exchange and LDAP, apparently Exchange doesn't use the standard LDAP ports, it uses 3268.
7. For "Bind DN" simply enter your username in domain\username format.

Seems obvious in retrospect but I figured I'd post it in case anyone else needed help.