LDAP BIND Problem with Exchange 2003

Make sure you have a Global Catalog server enabled (see AD Sites and Services, there is a tick box for NTDS Settings for each DC).

On Exchange server, ensure TCP/IP settings have correct DNS IP addresses used and is using a Static IP address.

Do you have any old Exchange 5.5 servers with ADC? The Exchange 5.5 LDAP Port can conflict with AD LDAP. Changing LDAP ports can fix this.

Also, make sure Firewall is not enabled between DC and Exchange which may block essential ports.

http://support.microsoft.com/default.aspx?scid=kb;en-us;288828

Be sure that the DC that the Recipient Update Service points to has the FSMO roles of both Global Catalog server and infrastructure master. To check the RUS properties, in the Exchange System Manager console, go to Recipients/Recipient Update Services and right click on the RUS(es) that you are using, then go to properties and look at the DC that is specified on the General tab. To check the infrastructure master role, open the AD Users and Computers console, right click on the domain name and click "Operations Masters." Click the Infrastructure tab to see which server has that role. Then, to be sure that this server is also a global catalog server, open the AD Sites and Services console and expand it to the [server name]/NTDS settings level. Right click on NTDS settings for the server and click Properties. Make sure the "Global catalog" checkbox is check; is not, check it to make the server a GC server. Then be sure this DC is the one specified in the RUS object.

Hope this helps!

Check that the GC isn't overlaoded and dropping LDAP requests.

There are a couple of different directory monitoring products that you can use to check this.

In an email to me, you asked about AD montioring products. There are tons, but my first thoughts are these:

http://www.activexperts.com/activmonitor/

http://www.aelita.com

http://www.netpro.com

In addition, Netpro offers an excellent free Ebook for troubleshooting AD issues.