How can missing suppression logic cause multiple sends?

Imagine a customer who browses your site every few days. No suppression logic in your browse abandonment flow means every single browse session fires the automation from scratch. By Friday, they've received five near-identical emails. They hit unsubscribe, or worse, mark you as spam. That's the real cost of missing suppression.

Suppression logic is the set of checks your automation runs before sending. It asks things like "Is this person already in this flow?" or "Did they complete it last week?" Without those checks, your automation treats every trigger as a brand-new opportunity, no matter how many times that person has already been through the sequence.

The most common gaps that cause repeat sends are:

• No active-flow check. The automation doesn't verify whether someone is already mid-sequence before letting them re-enter. Cart abandonment flows are notorious for this, since customers often add and remove items multiple times before buying.
• No cooling-off period. Even after someone completes a flow, there's no waiting window before they can enter it again. A "recently completed" suppression, even just 7 or 14 days, prevents the same message from hitting someone twice in quick succession.
• No cross-flow awareness. If someone is already in a post-purchase sequence, they probably shouldn't also be getting a win-back series at the same time. Related flows need to know about each other.
• No entry cap. Some setups have no lifetime limit on how many times a contact can enter a given flow. Setting a maximum (say, three times in a rolling 90-day window) gives you a safety net.

To audit your own flows, start by picking your highest-volume trigger (browse abandonment, cart abandonment, or post-purchase are good candidates). Pull a report of anyone who entered that flow more than once in the last 30 days. If you see the same contacts entering repeatedly, suppression is either missing or not enforced at the trigger level. The fix needs to happen at the entry point, not inside the flow itself, because by the time someone is inside, the damage is already done.

A practical setup that covers most cases: check for active membership in the same flow, check for completion within a defined window, and check for active membership in any related flows. Build all three into your trigger conditions, not as afterthoughts once the sequence is running.

If you're not sure where your flows are leaking, our SOS hotline is free. Bring your ESP and your flow structure and we'll help you find the gaps.