The Message opened entry point is triggered when a contact opens one of your emails.

It’s an effective way to track your contacts’ interest and engagement, allowing you to send targeted communications based on their actual interactions.
You can use this trigger, for example, to start a follow-up flow for those who opened a welcome email, or to send additional content to anyone who showed interest in a specific campaign.
How to set up the “Message opened” trigger.
1. Select the message type.
Choose whether to track the opening of a campaign or an autoresponder (if enabled).
2. Select the message.
Specify which email will trigger the flow.
3. Set “Repeat flow”.
This option lets you decide if and when a contact can re-trigger the sequence after having already entered it once.
If the Repeat flow switch is disabled, the contact will only enter the flow the first time they open the message. If enabled, the contact can re-enter the flow according to the mode you choose.
4. Set exit conditions.
If desired, set rules that remove the contact from the flow when they no longer meet certain criteria, keeping your communications relevant at all times.