Before you start
Things you need to know:
You must already have set up the triggered campaign to use.
The unsubscribe action campaign is designed to send only when a single contact unsubscribes, through methods like an unsubscribe form or a preference centre, and doesn't apply to bulk contact unsubscribes. Additionally, it only applies to contacts unsubscribing from a specific list, not when a contact is unsubscribed from the entire account.
Set up an unsubscribe action on a list
Go to Audience > Lists and select the Properties icon next to the list.
Under Campaign Triggers, for Unsubscribe, select SELECT CAMPAIGN.
In the Select campaign side panel, select the triggered campaign you want to send when a contact unsubscribes from this list.
Select the eye icon to preview a campaign.
Select SAVE at the bottom of the page.
The chosen campaign now automatically sends to your contacts when they unsubscribe from the list.