Every notification you write can go out as email, SMS, or both. Email works well when the message needs context, formatting, or links. SMS works best for short, time-sensitive reminders where participants need to notice the message quickly — a meeting starting soon, or a deadline today.
How to choose the channel
You set the channel on each notification, not once for the whole journey. Open the activity in your learning journey, go to its Notifications tab, open the notification you want, and pick email, SMS, or both. That means you can send a rich Invitation by email and a short "starts in an hour" nudge by SMS, from the same activity.
What SMS needs to actually send
An SMS only goes out when two things are true:
SMS is enabled for your organization. If it isn't, contact Knowly to turn it on.
The recipient has a mobile number in Knowly. SMS reaches the number synced to their account.
If either is missing, Knowly automatically sends that notification by email instead, so no one is left out. Because of that fallback, SMS is most reliable when you know your participants have mobile numbers on file — for example, when they registered with a phone number.
For where each channel fits in a well-paced journey, see Make the most out of notifications in Knowly.