Examine source code of Qverio Email Verifier

{
  "manifest_version": 2,
  "name": "Qverio Email Verifier",
  "version": "1.1.0",
  "description": "Instantly verify email addresses in your compose window. See validity, quality score, and risk signals before you send.",
  "homepage_url": "https://qverio.com",
  "permissions": [
    "storage",
    "https://mail.google.com/*",
    "https://mail.yahoo.com/*",
    "https://outlook.live.com/*",
    "https://outlook.office.com/*",
    "https://outlook.office365.com/*",
    "https://mail.zoho.com/*",
    "https://www.icloud.com/*",
    "https://mail.proton.me/*",
    "https://api.qverio.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*",
        "https://mail.yahoo.com/*",
        "https://outlook.live.com/*",
        "https://outlook.office.com/*",
        "https://outlook.office365.com/*",
        "https://mail.zoho.com/*",
        "https://mail.proton.me/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle",
      "all_frames": false
    },
    {
      "matches": [
        "https://www.icloud.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "email-verifier@qverio.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}