We got it to work by logging in with email addresses specified in AD. Here's our file in case anyone else has this issue.

#
# File generated by iRedMail (2012.04.18.13.55.17):
#
# Version:  0.7.4
# Project:  http://www.iredmail.org/
#
# Community: http://www.iredmail.org/forum/
#

hosts           = 172.x.,x.x:389
ldap_version    = 3
auth_bind       = yes
dn              = mydomain\my_bind_user
dnpass          = bind_pw
base            = ou=X X Users,dc=mydomain,dc=local
scope           = subtree
deref           = never
user_filter     = (&(mail=%u)(!(userAccountControl:1.2.840.113556.1.4.803:=2)))
pass_filter     = (&(mail=%u)(!(userAccountControl:1.2.840.113556.1.4.803:=2)))
pass_attrs      = userPassword=password
default_pass_scheme = CRYPT
user_attrs      = =home=/var/vmail/vmail1/%Ld/%Ln/Maildir/,=mail=maildir:/var/vmail/vmail1/%Ld/%Ln/Maildir/

Kind of lol.
Here's what we *wanted*..
Say my name is John Smith and my email address is john_s@mydomain.com. Our AD naming scheme would have my windows logon to be JSmith and lets say my password is 123. What we wanted is to have me have the same credentials for both windows and email. We tried so many different variables in the ldap-conf file, and finally settled on being able to log in to windows as JSmith/123 and log into email as john_s@mydomain.com/123. So it's successfully pulling my password, but we couldnt figure out how to make it work with the username. We were thinking the samaccountname string but couldn't get it to work properly. It's acceptable now but we'd like it to be the way i described with one username/password for both services. Thanks for the speedy reply!

I think we can be satisfied with logging in with Username: email address Password: Active Directory password.

Forgive me if i should create a seperate topic for this, but i have some other questions for you. We would like to archive every email that passes through our system. Our old server had some scripts that copied all emails sent and recieved into a MySQL database, but since we are using LDAP for the new system, no MySQL databases are being used. Do you have any suggestions? I might add that the BCC option is not an option as some of our 100+ users desire to keep the BCC functionality and i've read that if we use it for archiving, then it will remove the option for users. Thanks in advance!

Steve

Okay, we may look into that at a later date. That's not a pressing issue. I am having trouble with distribution groups though.
When i create a distribution group in Active Directory, add myself to it, and have one of my users send an email to the groups email address (testgroup@mydomain.com) i don't recieve the message and the sender gets an error stating that Recipient rejected - User unkown in virtual mailbox table. Any suggestions? I Can post any config files you need. Thanks in advance.