You will need to edit /etc/nagios/contacts.cfg
# 'efs' contact definition define contact{ contact_name efs alias Nagios Admin service_notification_period 24x7 host_notification_period 24x7 service_notification_options w,u,c,r host_notification_options d,u,r service_notification_commands notify-by-email host_notification_commands host-notify-by-email email efs@mail.fionavar.dd }
notification_commands can include commands for pager calls, sms messages, and so on while notification_options indicates what type of events this contact accepts notifications for. In this case warning, unknown, critical, and recovery for services, and down, unknown, and recovery for hosts.