Deepak Kashyap wrote:

We are connected in star topology with no domain controller. All the computers are connected to workgroup.

The Mail server (Ubuntu Server 8.04LTS+Postfix) runs on vmware running on Win2k pro with bridge network configuration.

Certain computers have access to internet but when the mailsever is working we are unable to access the net . We need to shutdown the VM / computer to be able to access the net.

Are there any ip conflicts in your network? There is no reason why a comp on a star topology should block net access to others. It may hog bandwidth but access should be possible for others unless your net connection itself is slow. Did you do the regular gateway ping, dns ping, dig and router login test when you were facing the problem?

I did a http sniff from my 'Host' OS which was showing unusual amount of traffic been sent out by the mailserver.

I felt it was because of a bounced mail which it keeps trying to send repeatedly, so I created a local mail archiving address , but this too does not solve the problem.

All computers access the internet via a netgear router.

Before a computer crash the same mailserver image used to work fine.

I am always vary of disk images for VMs. They are sensitive to touch. I have lost installations on my virtualbox due to sensitive disk images.