I had not changed the mode but I *may* have prepared the new server with the mode set to HTTPS whereas my old server was set to MIXED. I tried earlier today to move the server to HTTP mode (restart, test) and then back to MIXED mode (restart,test) just in case that would help resolve any problems.. but this didn't help.
I ran the fixperms script yesterday just-in-case and no luck either. I also confirmed the libraries as below (this is from my system)
# more zimbra.ld.conf
$ more /etc/redhat-release
Red Hat Enterprise Linux Server release 5 (Tikanga)
$ Linux 2.6.18-8.el5 #1 SMP Thu Mar 15 19:46:53 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux
I've been going through all the config files looking for any possible config problems but everything does look good. I need a way to debug this problem.. I don't know the internals of your LDAP schama or MySQL schema in order to understand the internal interaction for SMTP AUTH to work....