Centos 5.1 with ispconfig. It was everything OK till yesterday. Now... mail do not arrive. I'm sending mail from another host, and I did not receive "Mailer daemon reply" that mail can not be delivered. From another side (on ispconfig hosting), I do not receive any mail. Where is mail? Why it do not arrive to destination. And if there is problem, sender should receive "mailer daemon notification". Thanks in advance.