Information regarding the notifications:
Configuring notification rules in 12c is different from earlier releases.
The concept and function of notification rules has been replaced with a two-tier system consisting of Incident Rules and Incident Rule Sets :
1. Incident Rules: Operate at the lowest level granularity (on discrete events) and performs the same role as notification rules from earlier releases.
By using incident rules, you can automate the response to incoming incidents and their updates.
A rule contains a set of automated actions to be taken on specific events, incidents or problems.
The actions taken are for example : sending e-mails, creating incidents, updating incidents, and creating tickets.
2. Incident Rule Set: A rule set is a collection of rules that applies to a common set of objects, for example, targets, jobs, and templates.
To help you to achieve the Notification Rules configuration, refer those notes :
How To Configure Notification Rules in 12C Enterprise Manager Cloud Control ? Doc ID 1368036.1
EM12c How to Add and Configure Email Addresses to EM Administrators and Update the Notification Schedule ?Doc ID 1368262.1
EM12c How to Subscribe or Unsubscribe for Email Notification for an Incident Rule Set ?Doc ID 1389460.1