send notifications via email

Provide default configuration to send
alertmanager notifications to all receivers
including SMTP server.

PROD-18781

Change-Id: I299fbbee294e5c02a11c2746bccf4c8fe788e310
diff --git a/prometheus/alertmanager/notification/slack.yml b/prometheus/alertmanager/notification/slack.yml
index 2158adb..412e91f 100644
--- a/prometheus/alertmanager/notification/slack.yml
+++ b/prometheus/alertmanager/notification/slack.yml
@@ -1,11 +1,13 @@
 parameters:
   prometheus:
     alertmanager:
+      enabled: true
       config:
         route:
           routes:
             slack:
               receiver: HTTP-slack
+              continue: true
         receiver:
           HTTP-slack:
             enabled: true