I had the same problem using Ubuntu 6.06. I followed the above directions but still got the problem. I was able to resolve the problem. I think the answer was to have ldap bind to the local port by changing some of the DNS settings. Here are the settings I used.
I changed my hostname from
mail.example.com --> mail
/etc/hostname
mail
I then changed my hosts file
127.0.0.1 mail.localdomain --> 127.0.0.1 mail.example.com
/etc/hosts
127.0.0.1 localhost
127.0.0.1 mail.example.com mail
10.0.1.60 mail.example.com mail
I installed bind9 and configured DNS for internal lookups only.
bind host file
/etc/bind/example.com.hosts
$TTL 604800
@ IN SOA ns1.example. root.example.com. (
2006020203
604800
86400
2419200
604800 )
@ IN NS ns1
IN MX 10 mail
mail IN MX 10 mail
mail.example.com. A 10.0.1.160
IN A 10.0.1.160
ns1 IN A 10.0.1.160
mail IN A 10.0.1.160
www IN A 10.0.1.160
The I edited rc.conf to only use BIND for address look ups
/etc/resolve.conf
search home
nameserver 127.0.0.1
lookup bind |