Hello, I am currently experiencing and issue with my server. It is running centOS 5.3 with Plesk 10.4.4 LATEST micro updates(prior to the incident), as of Thursday the 23rd of January all mail service (sending and receiving) have failed throughout the entire server. When sending email from any domain name e-mail address on the server the following message is returned: The server bounces a message to the sender of an e-mail which is as follows: I have attempted service restarts for httpd, qmail, mysqld and crond. I have also made sure that ports 25, 110, 143 are all set to ACCEPT on the server. I have also upped the ulimit from 1024 to 2048. I have rebooted the server also just to clear the e-mail queues and to ensure that there where no issues.