---
title: Retro Scan · Cloudflare One docs
description: Retro Scan allows you to scan up to 14 days of old messages in your
  Microsoft 365 inboxes and check if your current email security solution missed
  any threats. Once you receive your Retro Scan report, you will be able to
  remediate malicious messages.
lastUpdated: 2025-11-05T17:19:20.000Z
chatbotDeprioritize: false
source_url:
  html: https://developers.cloudflare.com/cloudflare-one/email-security/retro-scan/
  md: https://developers.cloudflare.com/cloudflare-one/email-security/retro-scan/index.md
---

Retro Scan allows you to scan up to 14 days of old messages in your Microsoft 365 inboxes and check if your current email security solution missed any threats. Once you receive your Retro Scan report, you will be able to remediate malicious messages.

Note

Retro Scan is only available for Microsoft 365 accounts.

To start a free scan:

1. Log in to [Cloudflare One](https://one.dash.cloudflare.com/).

2. Select **Email security** > **Overview**.

3. Select **Start a free scan** > **Generate report**.

4. Enable your [Microsoft integration](https://developers.cloudflare.com/cloudflare-one/email-security/setup/post-delivery-deployment/api/m365-api/#enable-microsoft-integration). Once you enabled your Microsoft integration, you will redirected to a page wheer you will add your domains and speficy your current email security system.

5. Generate Retro Scan report:

   * **Connect domains**: Select at least one domain from your integration, then select **Continue**.
   * **Select current solution**: Select the email security tool you are currently using, then select **Continue**.
   * **Review details**: Review the details you previously selected. Then, select **Continue**. You will be notified by email once the report is available.

6. Go to your email inbox and select the link to view the full report.

7. On the Cloudflare dashboard, select **View report**.

The dashboard will display **Overview** and **Details** pages.

### Overview

Overview displays the total scanned domains. The overview shows you:

* [Disposition evaluation](https://developers.cloudflare.com/cloudflare-one/email-security/monitoring/#disposition-evaluation)
* Malicious threat types
* Malicious targets
* Malicious threat origins

### Details

Details allows you to review the first 1,000 emails assigned a disposition.

Select an email to review [details](https://developers.cloudflare.com/cloudflare-one/email-security/investigation/search-email/#details) about the message.
