Running Postfix on a server Fedora 7 with ISPConfig, when I send an e-mail to a distribution list (more than 10 users) at the any of the domains hosted on the server, the server goes very, very slow (I assume that it's making a process that take most of the resources), this happen for about 5 to 6 hours and then the system start working normally again. It is possible that postfix has a bug? or do I need to make any specific configuration for local distribution lists? (this does not happen if I send to 10 or more users at an external domain). Forget to mention that I'm using a relay from my ISP Thanks in advance for your ideas and help.