Mac OS X

From the "Applications" folder, open Directory Access and pull up the 'Services' tab. Highlight 'LDAPv3' and click 'Configure'. Click 'New' and give the new configuration a generic name – 'ldap' worked for me. Select your new configuration and click 'Edit'. 

In the 'Connection' tab, the 'Server name' is 'ldap.nebrwesleyan.edu'. Defaults work for everything else. In the 'Search and Mappings' tab, select 'RFC 2307 (Unix)' for 'Access this LDAPv3 server using'. The 'Search Base Suffix' is 'o=NebrWesleyan.edu,o=isp'. Select 'People' under 'Record Types and Attributes'. Change 'Map to <any> items in list' to 'Map to <all> items in list'. Underneath the list (which should only contain 'inetOrgPerson'), click 'Add'. Add the item 'inetMailUser'. 

Click 'OK', and 'OK' again, until you get back to the main Directory Access window. From here, go to the Authentication tab. Click the 'Add' button and select '/LDAPv3/ldap.nebrwesleyan.edu'. Repeat for the 'Contacts' tab.