If you go to https://dash.cloudflare.com you can use “Forgot your email” to get an email sent to the account owner. If that was to your corporate email you may be able to receive that.
Otherwise, if you are unable to log in to the account then you’ll need to take control of the DNS by changing the nameservers at your domain registrar to those for a new Cloudflare account or other DNS provider. You’ll need to ensure you have the details of your web host and mail provider to use for the new DNS setup. The domain isn’t currently proxied… https://cf.sjr.dev/tools/check?3ec7cf24d80046d8a62fdbc4d775e013#dns