Optional Delivery Features

You can enable optional features during the Delivery step when creating or editing a Message, Automation, or A/B Test. Each feature's purpose and settings are detailed here.

See the Message Reference for API equivalents.


Available features are dependent on which message types and platforms are selected.

Background Processing

The background processing option wakes the app and give it some running time to perform work, such as downloading content for future display. Data included in the push notification is available for background processing, e.g., to send URLs and then download that content. iOS only.

Toggle to enable.

Campaign Categories

Campaign categories are labels that group messages of a similar type or messaging strategy for aggregate reporting. Campaigns help you track the efficacy of both your individual messages and a messaging campaign as a whole.

Toggle to enable, enter a campaign category name, then click Add. Click the X next to any category to remove it. Category names have a 64-character maximum. Enter up to ten.


Campaign categories are listed in the Message Detail section of Message Reports.

Collapse Key

A collapse key suppresses a group of messages using the same same key value. Only the most recent message (using the same key) will be viewable.
Android & Amazon only.

Toggle to enable, then type the key in the text field.


Send the notification as a critical alert. Critical alerts are push notifications that play sounds and ignore the device's Do Not Disturb mode and mute switch settings. This delivery feature is available for iOS 12 and later only and requires a special entitlement from Apple.

Toggle to enable, then use the slider to select the alert volume level. Volume can be specified at 10% increments.


  • Critical alerts require a special entitlement issued by Apple, If you do not have this entitlement, you will not see this option in the dashboard.

  • These notifications should contain information that require a user to take immediate action.

  • Critical Alerts must be allowed by a user on their device.

Custom Keys

Custom keys are additional key-value pairs in your push notification payload for use by custom code in your app. You can use custom keys to pass additional campaign identifiers for analytics, pass user information to the device, control the look and feel of the app, provide image links, etc.

By default, a custom key is sent to push notifications on all platforms, but you can choose platform-specific keys as well if your message is going out to more than one platform, e.g., one imageURL for iOS and another imageURL for Android.

Toggle to enable, select a platform from the dropdown menu, then enter the key and value. Click Add Another for additional keys.

Delay While Idle

The delay while idle option delays delivery of your message until Firebase Cloud Messaging (FCM) detects that the device is active. This can increase the likelihood of the user engaging with the notification. Android only.

Toggle to enable.

Delivery Priority

The delivery priority option sends your notification using Firebase Cloud Messaging (FCM) high priority. When not enabled, messages default to normal priority. Android only.

Toggle to enable.


From Google's About FCM Messages: Delivery options: Setting the priority of a message:

High priority. FCM attempts to deliver high priority messages immediately, allowing the FCM service to wake a sleeping device when necessary and to run some limited processing (including very limited network access). High priority messages generally should result in user interaction with your app. If FCM detects a pattern in which they don't, your messages may be de-prioritized.


The expiration option discards your message if it hasn't been delivered to a device within a specific period of time.

Toggle to enable, then select the radio button for either Duration or Date & Time.

  • Duration: Enter the number of minutes, hours, or days past your defined send time to expire the delivery.

  • Date & Time: Enter the date and time when delivery attempts should cease.

Push Notifications
If a device is online, the notification will be delivered immediately. If a device is offline, the push service for each platform, e.g., APNs for iOS and FCM for Android, preserves the notification and attempts to deliver it as soon as it comes online, up until the expiration date.

For Web Notifications, if no expiration is set and a device is offline, the delivery service, e.g., Google or Mozilla, preserves the notification and attempts to deliver it as soon as it comes online, for a maximum of 28 days.

There is no way to remove a delivered push notification.

In-App Messages
Since In-App Messages are delivered via push notifications, they will not be delivered past the expiration date if the user has been offline. In addition, Airship will not display an in-app message past the expiration date.

Expiration (SMS)

The expiration option discards your message if it hasn't been delivered to a device within a specific period of time.
72 hours is the default. SMS Only.

Enter the number of hours, between 1 and 72.


A delivery group uses an identifier to group related notifications from your app into a single stack. Notifications bearing the same group identifier are stacked together. iOS 12 and later only.

Toggle to enable, then type an identifier in the text field.


Remember to use the same identifier for subsequent messages you wish to group.

Mutable Content

The mutable content option allows a notification’s content to be changed or downloaded before delivery. This feature is automatically enabled if media is defined in the message's Optional Features » Media settings. iOS 10 and later only.

Toggle to enable.

Require Interaction


Support for Require Interaction varies by browser and OS.

Enable the Require interaction setting to require your audience to interact with your web notification to dismiss it from the browser window. Web only.

Users may interact with a web notification in these ways:

  • Click the notification, which opens the message-defined URL, or the default Action URL.
  • Dismiss the notification.
  • Click the Settings icon or button on the notification.

Toggle to enable.

Start and End Dates

Start and end dates define the times during which your automation can deliver messages to your audience.

  • If you set a start date, the message status is automatically set to Pending until the specified date and time occur.
  • After the start date and time pass, the automation status changes to Active.
  • After the end date and time pass, the automation status changes to Completed, and the automation quits sending messages.
  1. Enable the Start Date and/or End Date options.
  2. Click the date field and either use the date picker, or enter a date in YYYY-MM-DD format.
  3. Use the dropdown menus to select the time and time zone.