How the cascade picks the next message
When a HubSpot workflow reaches the mxAURA action for a contact, the cascade decides which single message that contact gets:
- Alert pools first. If any assigned alert pool has a message the contact has not received, that wins.
- Scheduled pools are considered only inside their window.
- Nurture pools take turns (round-robin). A limited pool drops out when the contact has had every message; a recurring pool starts over.
- Within the chosen pool, the contact's next position.
- Filters on the pool (lists, properties) can skip a contact; that is a filtered outcome, not an error.
Variants: a message with several headers or summaries rotates them per contact (the shorter list recycles). Campaigns → Preview → Simulate shows the exact sequence a contact would get; it runs the same code.