Good morning everyone,

I have one question about notifications. I can't make it work properly :/.
So here is my issue :

I am using shinken 2.4.2 on Debian 8.2.
When a service isn't in a good state, I receive an e-mail (normal behaviour). I configured Shinken to send only one e-mail when a problem happens.
But when the problem concerns a specific service, I would like to wait for 30 minutes before sending this e-mail (to see if the problem is just temporary or not, for the CPU or RAM consumption for example).
I tried to use the attribute : first_notification_delay, but it's not working :/. I also tried services escalation... same result.

Would someone has an idea please ?

Please find below my configuration. Feel free to ask if you need more informations.
Code:
define service{
        hostgroup_name          windows
        service_description     Check Disque C:
        check_command           check_snmp_storage!C:!90!95
        check_period            24x7
        check_interval          3
        retry_interval          1
}
Code:
define host{
        contact_groups          admins
        notification_interval   0

        host_name               INDRE-SRV-VCR
        hostgroups              indre, veeam, windows
        address                 172.16.29.230

# GPS
        _LOC_LAT                47.20019
        _LOC_LNG                -1.673658
}
Code:
define contact{
        contact_name            admin
        alias                   Admin
        email                   jordan.henry@aps-si.com
        pager                   0600000000
        password                admin
        is_admin                1
        expert                  1
        notificationways        email
        host_notifications_enabled      1
        service_notifications_enable    1
        can_submit_commands             1
}