Why you can't do this in one step

Acoustic Campaign automatically adds contacts to the Master Suppression List (MSL) when they opt out, hard-bounce, or file a complaint. It doesn't automatically suppress contacts just for going inactive — not opening or clicking isn't the same as opting out. So if you want to stop sending to contacts who never reengage, you need to identify and suppress them yourself.

Note: The platform doesn't suppress contacts based on inactivity on its own. You need to manually manage suppression for inactive contacts, using the steps below.

Step 1: Add a decision point in your journey

1. Open your reengagement journey.
2. Add a decision point to identify inactive contacts.
3. Set the decision criteria — for example:
   • Did not open email
   • Did not click in email
   • Other engagement criteria based on your goals

Step 2: Tag inactive contacts

Route inactive contacts to an exit path, then tag them using one of these methods:

• Update Profile action — mark the contact with an inactive flag or status.
• Add to Contact List — create a dedicated contact list for inactive users and add them automatically when they meet your inactivity criteria.

Step 3: Export inactive contacts

After your journey completes:

1. Go to the contact list or segment containing your tagged inactive contacts.
2. Export the list of inactive contacts.
3. Save the file in CSV format.

Step 4: Add contacts to your Master Suppression List

1. Go to Suppressions > Master Suppression List.
2. Click Upload or Import.
3. Select your exported CSV file.
4. Confirm the upload to add the contacts to your MSL.

Once this is done, these contacts stop receiving campaigns, which helps you keep engagement rates healthy, improve deliverability, and avoid spending send volume on subscribers who aren't opening anyway.

Set your own inactivity criteria

Before you suppress anyone, decide what "inactive" means for your program:

• No opens or clicks in 90 days is a common starting point — adjust it to fit your own send frequency.
• No engagement across multiple reengagement attempts.
• Run this review on a regular cycle — quarterly or twice a year works for most senders.
• Write down your criteria so your process stays consistent across campaigns and teams.

Tip: Give contacts a real chance to reengage before you suppress them — send at least one dedicated win-back attempt through a campaign or journey first.

Frequently asked questions

Can I automatically add inactive contacts to the Master Suppression List?
No. Acoustic Campaign only suppresses automatically for opt-outs, hard bounces, and complaints. For inactivity, you need to follow the steps above.

What's the difference between suppression and unsubscribe?
An unsubscribe happens when a contact opts out themselves — they're added to the MSL automatically. Suppression is something you do yourself, usually based on inactivity or another business rule.

Can I remove contacts from the Master Suppression List later?
Yes. Make sure you have proper consent and a valid reason before you reengage a previously suppressed contact.

Will suppressed contacts see any of my emails?
No — contacts on the Master Suppression List don't receive any emails from your organization in Acoustic Campaign.

Next steps

• Create a suppression list
• Master suppression list
• Suppression lists
• Opt-out and suppression settings