> ## Documentation Index
> Fetch the complete documentation index at: https://moengage-docs-mcp-segmentation-tool-belt.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Why Does Encryption or Decryption Fail in Email Campaigns?

> Fix encryption or decryption failure errors in MoEngage email campaigns by passing email data in the correct encrypted format for PII protection.

## Problem

When sending an Email campaign during testing, the message “Users removed due to Encryption/Decryption failure” is received. Even though encryption is enabled for one attribute, it is not utilized in the campaign.

<img src="https://mintcdn.com/moengage-docs-mcp-segmentation-tool-belt/S5T4So9_9UMlTMby/images/moengage_21f333.png?fit=max&auto=format&n=S5T4So9_9UMlTMby&q=85&s=313a97c11dbe64cfe77dca7919605304" width="1600" height="634" data-path="images/moengage_21f333.png" />

## Solution

* This error indicates an issue with how personally identifiable information (PII) is being handled in your campaign.
* This can occur even if you have enabled the *PII Encryption* feature (**Encrypt attribute** toggle) for your workspace.
* You should pass the email data in an encrypted format to ensure the expected behavior of the *PII Encryption* feature.
* Enabling the *PII Encryption* feature (**Encrypt attribute** toggle) will automatically encrypt future email data, preventing this issue.
  <img src="https://mintcdn.com/moengage-docs-mcp-segmentation-tool-belt/-CPXQ8cFB42Sdqri/images/moengage_53a0b3.png?fit=max&auto=format&n=-CPXQ8cFB42Sdqri&q=85&s=334c04465760547770e13bc423634e25" width="1600" height="811" data-path="images/moengage_53a0b3.png" />
  <Warning>
    PII data will be encrypted using server-to-server (S2S), SDK, and user import version 2. However, the user import version 1 is not supported for this purpose.
  </Warning>