Segment-triggered flows are used to email subscribers when they are added to a segment. In most cases, date property-, list-, or metric-triggered flows can more efficiently accomplish what can be done with a segment triggered flow.
Contacts can only receive a segment-triggered flow once. This is why if you're building a post-purchase flow, for example, you should use a metric-triggered flow instead of a segment-triggered one. Even though it is possible to build a segment of customers who placed an order, a metric-triggered flow is more appropriate in this case because you likely want customers to receive a post-purchase every time they buy, not just the first time.
Configure a Segment-Triggered Flow
To create a segment-triggered flow, create a new flow and select Segment from the Trigger Setup pane in the lefthand sidebar.
Next, you will be prompted to select the segment that will trigger the flow. Once you set a particular segment to trigger the flow, you will not be able to change it to a different segment. In order to do this, you will need to clone the flow and change the segment that triggers the flow.
How a Segment-Triggered Flow Works
Whenever someone is added to the segment you select, they will enter the flow.
Contacts can only receive a segment-triggered flow once. If someone is removed from a segment and then re-added to that same segment, they will not re-trigger the flow. If someone is removed from a segment before the end of the flow, they will stop receiving the email sequence.
If you manually update a segment that's set up to trigger a flow, new members who instantly populate due to the update will not automatically enter the flow. When a flow is triggered by a segment, only those who are added to the segment organically, based on the established segment definition, will be scheduled.
When you create, edit, or update a segment, new populated members will not be queued by default. This ensures if you make a mistake with your definition or don't immediately want all members of a segment to enter a flow, you don't have to worry. If you do want to push all members of a segment into a connected flow after manually updating the definition, you will need to back-populate the flow.
At send time, Klaviyo checks to ensure that each potential recipient is still part of the segment triggering the flow. Say, for example, you edit the definition of a segment and some of the contacts queued up for the connected flow no longer meet the segment's conditions. At send time, we will re-verify that these recipients qualify and, when they fail the check, they will be skipped.
Recipients will only receive emails within a flow if they are still a member of the connected segment at send time.
Check out these articles on other flow types: