Yes, users have the ability to deregister from channels to stop receiving messages, but the opt-out method will differ according to the channel.
Refer to the Conversation API Opt-in & Opt-out section of the Sinch Documentation site for more details.
Learn more about Sinch Conversation API.
Watch this demo video to get a feel for how to make the most of connected conversations using Conversation API and the easily accessible demo on the Sinch customer dashboard:
The video shows you how you can get stared with Sinch using one simple API to reach customers over multiple channels and deliver a mobile-first experience that's out of this world.
Useful Links: