# Storing, processing, and replicating notifications using notification hubs in AWS User Notifications
<a name="notification-hubs"></a>

Notification hubs are an account-level setting that identify the AWS Regions where you store, process, and replicate notifications. You must select at least one notification hub before you create any notification configurations. If you have no notification hubs, the console prompts you to choose at least one before you create a notification configuration. You can also edit notification hubs from **Notification hubs** in the navigation pane. Currently, you can select up to three Regions. 

**Note**  
 If you want to manage notification hubs, ensure you have the appropriate permissions. For more information, see [Resource-level permissions in AWS User Notifications](resource-level-permissions.md). 

**Important**  
Notification hubs only set the Regional boundaries of notifications. User Notifications stores the notification configuration's data in the default Region, US East (N. Virginia). This data is also stored in individual Regions that you have configured rules for. For example, say that you create a configuration that receives Amazon CloudWatch Alarm notifications about events in Europe (Milan) and Europe (Frankfurt). User Notifications creates the notification configuration in US East (N. Virginia). It then replicates the configuration to Europe (Milan) and Europe (Frankfurt). 

**Important**  
User Notifications uses Amazon Simple Email Service (Amazon SES) API endpoints to deliver email notifications. Amazon SES API endpoints aren't available in all Regions. For a list of Regions that support Amazon SES API endpoints, see [Amazon Simple Email Service endpoints and quotas](https://docs.aws.amazon.com/general/latest/gr/ses.html#ses_region) in the *Amazon Web Services General Reference*. User Notifications routes emails about events originating from Regions that aren't supported as Amazon SES API endpoints through US East (N. Virginia). If wanted, you can turn off the receipt of notification for events that originate in Regions that Amazon SES API endpoints don't support. To do so, don't configure emails for notification configurations that contain events in these Regions.

**Topics**
+ [Adding or removing a notification hub in AWS User Notifications](nhr-add-remove.md)
+ [Enabling or disabling opt-in Regions in AWS User Notifications](nhr-optin-out.md)