Correspondence deserves thoughtful protection.

The correspondence workflow in practice.

For an individual, the expectation is straightforward: nobody else should see private letters by guessing a URL. For a business, access must also account for the relevant organisation, department, user role and matter. PDF previews, search results and evidence exports all require the same care as the original document.

Public QR verification is a particular example of balancing usefulness and confidentiality. The verification page should disclose only approved minimum information, never the full underlying letter by default. Security claims on the website will reflect controls that have been implemented and independently verified.

A particularly important threat is insecure direct access to document identifiers. A public reference or predictable URL must never allow one customer to download another person’s correspondence. Every document view, thumbnail, search result and export needs server-side permission checks against the appropriate tenant and user. Signed temporary links can be useful, but they need short lifetimes, suitable scopes and a way to revoke access where required.

Security also includes the work that happens off-screen. Staff handling print-and-post jobs need controlled access to production documents, and operational logs must not unnecessarily copy private letter content. Background queues, payment integrations and outbound email each introduce separate risks that should be assessed before launch. A minimal public website with no account login should not be misrepresented as evidence that the future full platform has already passed security certification.