You can set an expiration delay or a Time to Live (TTL) in hours for your notification. The notification won't be displayed if the device doesn't receive the notification or doesn't come back online within this time.
It's interesting to avoid the users receiving a waterfall of push notifications when they go back online. It's especially true for Web Push since desktop can stay closed for a long time.
By default, Batch sets a TTL of 14 days for all the notifications you send. If your user's device comes back online before being off for two weeks, it will display the last notification you sent to your user (iOS) or all the notifications sent over the previous two weeks (Android and web push).
Note : if the notification has already been sent and received, it's not possible to remove it from the notification center.
Set the the TTL globally
In the Settings > Push Settings section of your dashboard, you can override the default Batch TTL, for all the campaigns (know more here).
Set the TTL per campaign
You can set a TTL for a specific campaign,