Hello, I received few mails from my users saying that there are few emails that didn't arrive to their Inbox folder. There are few from yahoo and others with register domains. I saw the mail.log and display the following info: Lost connection with q1.netfirms.com[xx.xxx.xx.xx] while receiving the initial server greeting) mail.domain.com How can I do to fix it? I have ubuntu hardy heron, postfix, php5, mysql...from Perfect Server 8.04 tutorial. Hope to hear soon! Thank you very much!! I forgot to say that I have few virtual sites through sites-available and sites-enabled running in the server. With different IPs.