From a PDF to a record that outlives the mailing.

1. Upload the document to a matter

Mail belongs to a matter, so that is where it starts. The PDF is hashed on arrival and checked for the things that make a physical mailing fail rather than the things a viewer complains about: an unsupported page size, a page count that changes the price, and content in the region where the address panel is printed.

send.legal prepends its own cover sheet, so the address panel is printed over a page it generated rather than over the first page of your letter. That is not a stylistic choice — orders with content under the address region are cancelled by the print vendor, and the discovery usually happens days later, by the person who missed the deadline.

2. Choose a recipient and a mail class

Recipients come from the matter's parties or the firm address book. The selector is labelled mail class, because "service" means something specific in this profession and it is not what a postal product is.

• USPS First-Class — no tracking, the ordinary case.
• Certified Mail — a mailing receipt and delivery history.
• Certified Mail with electronic Return Receipt — the above, plus an electronic record of the signature. It is an electronic record, not a physical green card.
• Priority (1–3 day) — an estimated transit window, not a delivery commitment, and not Priority Mail Express.

The price of the mailing is calculated and shown before anything is submitted, including the surcharge that applies past six sheets. Nothing is sent and nothing is charged until someone reviews it and presses Send.

The same document can go to one recipient or to many. Each recipient becomes its own mailpiece with its own tracking and its own timeline, and the roll-up stays honest about it: a mailing reads 3 delivered · 1 returned, never a flat "delivered".

3. Send — and freeze what was sent

At the moment a mailing is created, the recipient address is copied into an append-only snapshot. From then on it is a fact about that mailing rather than a pointer to a contact record. A paralegal correcting the address book next March cannot change what this record says was on the envelope, and the record notes who accepted an address correction and when.

The letter as the vendor rendered it for print is fetched and stored at creation time, so the record can show the pages that were actually printed rather than the file that was uploaded.

4. Follow the timeline

Provider events are received as they happen and reconciled against the provider afterwards, because a webhook that is never delivered looks exactly like a mailing where nothing happened. Every observation is stored with two timestamps and the source that reported it.

Two rules govern what the timeline is allowed to say. Nothing is ever rewritten — events are added, never edited or reordered, and a correction is an annotation rather than an erasure. And a status is never promoted beyond what was observed: a print vendor's "completed" is its own documented approximation of delivery, so it is recorded as an estimate, and only an actual USPS delivery scan is recorded as delivered.

When coverage cannot be substantiated, the record says so. The guarantee is not that no event is ever missed. It is that send.legal either preserves an observed transition or reports that the coverage is incomplete.

What you end up with

A Mailing Record PDF per mailing, and a firm-wide audit history that is searchable and exportable as CSV or JSON. The JSON export carries each entry's hash, the hash before it, and the chain head — so whether the exported sequence has been altered is a question someone can answer without a send.legal account and without asking us.