Weird Connection problems

[carnold]

Using 5.0.10 on SLES10 SP1 with self-signed certificate. This problem was first seen while using kontact mail client now it shows itself with entourage on OSx 10.5.2. What happens is there is always a "timeout" or "connection dropped" error. With kontact it was something to the effect of connection timeout and will be re-established if possible. With entourage it appears as the same just different wording:
Connection to the server failed or was dropped.
I asked this before and got 0 responses on this forum. The zimbra log does not show any errors that are helpful (maybe i was looking in the wrong place?). Can it have to do with the self-signed certificate? Is there any kinda trace that can be run to find the problem?

[uxbod]

Are you going through a proxy or firewall at all ?

[carnold]

No proxy and the firewall is at the internet connection then there are 2 switches plugged into the firewall (all on the trust side). So no, we go through the switch...Well now that i think about that, that is not entirely true. The mail server is on the "optional" side and the problem pc is on the "trust" side, so yes it goes through the firewall. Kepp in ming this has worked in the past, just recently started seeing this first in kontact then moved to zimbra desktop and now to entourage 2k8.

To elaborate a little more on the setup:
the firewall has only trust side. What was done was a secondary ip was placed on the trust port. The secondary ip is for another network/subnet (DMZ). The mail server sits on this secondary ip subnet. This secondary ip is plugged into a switch. Then there is another network/subnet that sits on the trust side. This network/subnet plugs into an entirely different switch. The DC and Pc's sit on this network. The firewall has a policy that allows "all" trust traffic (doesn't matter if you are on the sec ip or the other network) to pass through. Hope this helps clarify things (please don't tell me what a bad setup this is as i just "load the wagons").