Conditional Access

Sendmaster web extension

Sendmaster is a browser extension that displays SPF, DKIM, and DMARC DNS records for the website you are currently viewing. This document describes the data the extension handles and where it goes.

What the extension does

When you click the toolbar icon on a tab, the extension reads the hostname of that tab, derives the root domain, and queries DNS TXT and NS records for it. The results render inside the popup. The only network traffic generated by the extension is the DNS queries described in the next section.

DNS query destinations

DNS queries go to one of two public DNS over HTTPS resolvers:

  • Cloudflare: https://cloudflare-dns.com/dns-query
  • Google: https://dns.google/resolve

The extension alternates between the two providers on each lookup. Both providers receive the domain name being queried and the IP address of your device. Their respective privacy policies apply to those requests:

Data stored locally

The extension uses chrome.storage.local to keep three small pieces of data on your device:

  • A list of DKIM selectors you have added through the popup form.
  • A cache of recent DNS lookup results, keyed by domain, valid for 600 seconds.
  • The name of the most recent DNS resolver used, so the next lookup alternates to the other one.

All of this stays on your device. Removing the extension or clearing its storage through your browser removes it.

What the extension does not collect

The extension contains no analytics, no telemetry, and no remote backend. It reads no personal information, browsing history, page contents, cookies, form data, or credentials.

Permissions

  • activeTab: grants temporary access to the URL of the tab that is active when you open the popup, so the extension knows which domain to inspect.
  • storage: lets the extension save the local cache, manual selectors, and provider preference described above.
  • Host access for cloudflare-dns.com and dns.google: lets the popup send DNS over HTTPS requests to those two resolvers.

Children

The extension is suitable for any audience and collects no information from any user, including children.

Changes to this policy

If the way the extension handles data changes, this document will be updated and the date at the top revised. Continued use of the extension after such an update means you accept the revised policy.

Contact

For questions about this policy, contact lewis@conditionalaccess.uk