You can set custom notification template to be sent to the developers who performs New Key Registration from developer portal as listed below: 

In APICC Go to Design --> Notification Templates --> Add Template Set --> Key Registration

Here you can add your custom template to be sent if there is any specific requirement on the email format and details. If otherwise by default the developer will receive the default email notification. 
 
Once you create the custom notification template go to Design --> Packages --> <Package>--><Plan>--> Notification Settings and pick the notification template that you created and hit save so the new custom template gets active and the new custom email gets sent out to the developer users who request for new API keys for that package. 

Please Note: This notification email setup is based in Package/Plan level and not based on area level.