---
title: GroupSessionMessenger.DeliveryMode.reliable
framework: groupactivities
role: symbol
role_heading: Case
path: groupactivities/groupsessionmessenger/deliverymode-swift.enum/reliable
---

# GroupSessionMessenger.DeliveryMode.reliable

An attempt to ensure the delivery of messages to known participants.

## Declaration

```swift
case reliable
```

## Mentioned in

Synchronizing data during a SharePlay activity

## Discussion

Discussion Use this approach to send messages that are critical to the experience you create. The GroupSessionMessenger enqueues a message until it is successfully transmitted to all known participants.  The system doesn’t guarantee delivery to participants who join a group session after you send a message, or who leave the group prior to delivery.

## See Also

### Getting the delivery mode options

- [GroupSessionMessenger.DeliveryMode.unreliable](groupactivities/groupsessionmessenger/deliverymode-swift.enum/unreliable.md)