CentOS/cPanel support needed...

I have a web script that sends emails (alerts) to subscribers. The script appears to have stopped working this morning for some domains, but not all. It might be that the server is unable to contact those domains or in some way has been blocked etc, I just don't know. I am looking for someone to provide support in resolving the issue. This is a CentOS server with cPanel. If you feel you are able to help please let me know your experience and when you are able to help get the script running again. Some error messages were received last night indicating that dovecot might be involved in the issue. The messages indicate that there was an attempt to run a deleted file, namely dovecot.