1. JSON is not a transfer method.
2. Display name.
3. It enhances the SQS distribution model from one-to-one to one-to-many.
4. Email, SMS, mobile notifications.
5. Create a separate notification topic in each region and subscribe each department to that topic. Separate metrics can be collected this way for each topic.
6. If your subscription has been confirmed by the recipient.
7. Disable anonymous access and create a user with a secret key and an access key that will have the permission to only send to this topic. Provide the user to the outside service provider and direct them to use the AWS CLI with the appropriate commands to publish to the topic using the user secret and access key provided.