Icinga2 Mail Notification Issues

I have a CentOS 7 machine stood up running an Icinga2 master with several hosts reporting. I have checked out a multitude of topics and cannot seem to find a resolution to my issue. When forcing a custom notification, I receive a mail notification, however, if something goes to critical, Icingaweb2 says it sent a notification but I never receive one. I have looked at many posts over the last couple of days but cannot find a resolution.

I have also read over the notification & notification command documentation but cannot seem to find the cause of my misstep.

Here are some examples of my configuration:

notification template:

 template Notification "mail-host-notification" {
      command = "mail-host-notification"
      interval = 15m

      states = [ Up, Down ]
      types = [ Problem, Acknowledgement, Recovery, Custom,
                FlappingStart, FlappingEnd,
                DowntimeStart, DowntimeEnd, DowntimeRemoved ]

      vars += {
        // notification_icingaweb2url = "https://www.example.com/icingaweb2"
        notification_from = "Icinga 2 Host Monitoring <email_changed>"
        notification_logtosyslog = false
      }

      period = "24x7"
    }

    /**
     * Provides default settings for service notifications.
     * By convention all service notifications should import
     * this template.
     */
    template Notification "mail-service-notification" {
      command = "mail-service-notification"
      interval = 15m

      states = [ OK, Warning, Critical, Unknown ]
      types = [ Problem, Acknowledgement, Recovery, Custom,
                FlappingStart, FlappingEnd,
                DowntimeStart, DowntimeEnd, DowntimeRemoved ]

      vars += {
        // notification_icingaweb2url = "https://www.example.com/icingaweb2"
        notification_from = "Icinga 2 Service Monitoring <email_changed>"
        notification_logtosyslog = false
      }

      period = "24x7"
    }

host example, all configured the same:

object Host "hostname_changed" {
  import "generic-host"
  address = "123.123.123.123"
  vars.agent_endpoint = "hostname_changed"
  vars.os_type = "windows"
  vars.notification["mail"] = {
    groups = [ "icingaadmins" ]
  }
}

apply rules for notifications

apply Notification "mail-icingaadmin" to Host {
  import "mail-host-notification"
  user_groups = host.vars.notification.mail.groups
  users = host.vars.notification.mail.users

  //interval = 2h

  vars.notification_logtosyslog = true

  command_endpoint = host.vars.agent_endpoint
  assign where host.vars.notification.mail
}

apply Notification "mail-icingaadmin" to Service {
  import "mail-service-notification"
  user_groups = host.vars.notification.mail.groups
  users = host.vars.notification.mail.users

  //interval = 2h

  vars.notification_logtosyslog = true

  command_endpoint = host.vars.agent_endpoint
  assign where host.vars.notification.mail
}

user I configured

object User "username_hidden" {
  display_name = "displayname_hidden"
  enable_notifications = true
  states = [ OK, Warning, Critical ]
  types = [ Problem, Recovery ]
  email = "email_hidden"
  groups = [ "icingaadmins" ]

  vars.notification["mail"] = {
    groups = [ "icingaadmins" ]
    users = [ "icingaadmins", "username_hidden" ]
  }
}

object UserGroup "icingaadmins" {
  display_name = "Icinga 2 Admin Group"
}

After more investigation, I’ve found that it is sending the notification, but only to the default “icingaadmin” user that comes preconfigured, even though I am specifying both the default user and the user I created with my e-mail.

I have changed the e-mail address of the default user and it now works. I can not figure out why it will not allow me to add a different user to receive e-mails.