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How to use our suppression system (and why it’s easy and secure)

Frequently Asked Questions

How to use our suppression system (and why it’s easy and secure)

Step-by-step instructions.

Last updated on 31 Jan, 2026

To ensure only new names are added to your list when you run Lead Ads on Civic Shout, we offer the easiest-to-use suppression tools around.

Our advanced SHA-256 hashing tool handles all data processing in your browser via Javascript—ensuring data never leaves your machine during the hashing process. In fact, you can even use it when you’ve turned off your WiFi for total peace of mind. The system is lightning fast and notably more secure than outdated MD5 systems.

Using our suppression system couldn’t be any easier.

Here’s how to do it:

  1. From your CRM, export a CSV of your full email list, with at least one column labeled "email"

  2. Visit our SHA-256 hashfile generator, click “choose file”, select your CSV file, and click the "Generate Hashfile" button

  3. Once your file has finished hashing – which shouldn’t take more than 20 seconds at most – click the "Download Hashfile" button

  4. Sign into your Civic Shout account, use the navigation options on the left side to go to the “Suppression” tab, click choose file, select the hashfile you downloaded from our hashing tool, and click “Upload Hashed CSV.” This should take roughly 5 minutes per one million rows in your file.

That’s it – you’re all set once you’ve completed those simple steps.

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