> ## Documentation Index > Fetch the complete documentation index at: https://help.chatarmin.com/llms.txt > Use this file to discover all available pages before exploring further. # How to Opt-Out "Message Undeliverable" Contacts > Chatarmin guide: How to Opt-Out "Message Undeliverable" Contacts *** ## Message Undeliverable 🚫 *** You will find the reason for this error here: [Flow Errors](/troubleshooting/flow-errors) If you have contacts in your list who **cannot receive messages**, you can easily **opt them out in bulk**. This prevents further failed delivery attempts and keeps your audience list clean. *** ## Clean Up Undeliverable Contacts 📩 *** ## Go to Segments 🔍 Navigate to **Segments** in your Chatarmin dashboard: 👉 [Chatarmin Dashboard – Segments](https://chatarmin.com/dashboard/audience/segments) * Click **Create Segment** and give it a name, e.g. *“Message Undeliverables”*. * Under **Add filter**, select **Cannot receive message** and set the filter to **at least 3**. Chatarmin help center image ✅ This ensures the segment only includes contacts who repeatedly failed message delivery. * Now save the filter and Review Segment Chatarmin help center image * Save the segment. Chatarmin help center image ### Bulk Opt-Out 🚫📩 Once the segment is created: 1. Open the **three dots (⋮)** menu on the segment. Chatarmin help center image 2. Select **Bulk Actions**. Chatarmin help center image 3. Choose **Consent → Opt-out**. Chatarmin help center image This will set all contacts in the segment to **opt-out**, so they will **no longer receive messages**. Customers who were opted-out can **always opt back in** later if they register or subscribe again. ### 🔄 Keep Segments Updated You can **refresh and update your segments regularly** to continuously filter out any new **“message undeliverable”** contacts. Chatarmin help center image