At 14:52 26-05-2012, Kwame Saidi wrote: >root at localhost ~]# tail -f /var/log/maillog >May 24 11:16:22 nagios sendmail[13393]: My unqualified host name >(nagios) unknown; sleeping for retry Sendmail cannot determine the host name as the server is not configured correctly. Once that is fixed, test whether you can receive mail sent from that mail server. Regards, -sm