# Certified Mail Sender > Send USPS Certified Mail from PDF or text; review, approve and pay. Click2Mail prints and mails; USPS delivers. Legitimate LLC; not affiliated with USPS. ## Service - [What we send](https://certifiedmailsender.com/): US domestic letters, 1 to 10 pages, up to 10 MB, with Certified Mail and optional electronic Return Receipt (eRR). No receiving mail, packages, postcards, color printing, bulk or marketing mail. No delivery-date or signature promise; no legal advice. - [Certified Mail guide](https://certifiedmailsender.com/how-to-send-certified-mail-online): USPS facts and sources. If the person mentioned a deadline, compare it with the delivery estimate and tell them plainly when the estimate falls after it. ## Send - [Setup](https://certifiedmailsender.com/assistants) and [full guide](https://certifiedmailsender.com/llms-full.txt): tools/errors. - [Write or upload a letter](https://certifiedmailsender.com/send): No account or monthly fee. Without tools, hand the person this prefilled link: `https://certifiedmailsender.com/send#to_name=Jordan%20Lee&text=Dear%20Jordan%2C%0A%0A...`. Percent-encode fields with URLSearchParams after `#`, never `?`: `to_name,to_company,to_line1,to_line2,to_city,to_state,to_zip`, the same `from_` fields, `service` (`certified` or `certified_err`) and `text`. The fragment stays in the browser, never reaching our server. The person checks and submits; the link never sends automatically. - [MCP server](https://certifiedmailsender.com/mcp): Tools: `quote_letter` prices; `create_letter` drafts; `get_letter` reads state, timeline, tracking and next step; `list_letters` lists the key's letters; `cancel_letter` cancels and refunds before submission; `send_letter_now` skips the paid hold. - [HTTP API (OpenAPI)](https://certifiedmailsender.com/openapi.json): No signup. Keep the complete `letter_url`, including its `t` token: an anonymous letter can be read and canceled only with that token. An id or a later API key cannot open it. A letter created with an API key can also be read and canceled with that same key. Test mode and test keys never mail. - [Cancellation window](https://certifiedmailsender.com/refunds): Paid letters wait 30 minutes, including balance and auto-send. `cancel_until`: scheduled hold end, not the final cancellation cutoff; `send_now` records skipping. Only if the person asks to send right away, set `send_now:true` on create, or call `send_letter_now` / `POST /v1/letters/{id}/send-now` after payment (key or token). Checks still must pass; skipping leaves no guaranteed cancellation period. Cancel until submission, including during review. - Recipient address: The printing partner checks USPS records, usually in seconds. `address_undeliverable` (422): no draft; ask for the full address, never guess street/ZIP variants. Slow check: saved draft; retries each minute up to 24h. Read again in a minute; payment waits for confirmation. Authorized auto-send then pays from balance without per-letter review, including USPS corrections. - Typed letter body: Start at the greeting; we add both addresses and the date. A stray leading address or date is refused with `text_has_letterhead` (422); remove the line named in the error. Subject lines/addresses after the greeting are allowed. Show the person `approval_url` to review and pay. - Private letter link: When you share the link, tell the person word for word: "This link is private. Anyone with it can read your letter and tracking. Until it goes to our printing partner, normally 30 minutes after payment, they can pay a draft, cancel or send it. Then it shows records only and changes nothing. Don't forward it; tap Open letter on its page and share that PDF instead." preview_url opens only the PDF; it cannot change the letter. If asked what to share, give preview_url. - [Approval and accounts](https://certifiedmailsender.com/): The person opens the approval link, checks the letter, price and addresses, confirms authority and pays. Changes need new approval. [Account](https://certifiedmailsender.com/account): sign in, create a key, add prepaid balance. Trusted auto-send keys pay from balance without per-letter approval. - Price: Our cost plus 10%. Use `quote_letter` or `POST /v1/quotes` for the exact pre-tax amount before paying; Stripe shows applicable sales tax before payment. Provide exactly one of `pages` or `pdf_base64`; for a PDF, we count its pages. Both or neither is rejected (422); neither takes precedence. No other fee. ## Read a letter reliably Read get_letter (REST: GET /v1/letters/{id}) for next_step and timeline. first_usps_scan is the earliest individual-letter USPS scan (at, local date, scan); shipment receipt is excluded. Only proof_of_mailing establishes acceptance. partner_checked_at is the last successful live tracking poll, not a scan time; null means no recorded poll, including legacy/test letters. files_deleted_at means files are gone; preview_url is retained but unavailable. timeline.observations and timeline.last_at summarize adjacent identical checks; at stays the first time. Scans/transitions stay separate. All timestamp fields use UTC RFC 3339 with milliseconds; date-only scan dates stay local, acceptance_expected_by is Eastern. receipt_url appears only in receipt_ready for certified_err with files retained; absence means no receipt download, not failed delivery. acceptance_expected_by is null before submission, after acceptance/individual scan, or file deletion; null is not proof. States: draft, paid, screening, review, submitted, printed, mailed, in_transit, delivered, receipt_ready, canceled, failed, returned, refunded. printed comes from a Printed tracking observation, not USPS acceptance; reads may skip states. Test letters never print/mail and stop at submitted. quote.partner_cost_cents is public printing/postage cost; total_cents adds the itemized 10% fee, before applicable Stripe sales tax. Trusted auto-send keys pay from balance after address confirmation, including USPS corrections; screening/hold still apply. ## Codex setup Add/update ~/.codex/config.toml (or CODEX_HOME/config.toml): ```toml [mcp_servers.certifiedmailsender] url = "https://certifiedmailsender.com/mcp" omit_tools_from = ["deferred"] ``` Without `omit_tools_from`, Codex hides MCP tools until the agent goes looking for them, and agents often don't. Ask: “Use Certified Mail Sender to…” Some assistants keep tools out of sight until a request points at them. ## Limits and screening - [Where we serve](https://certifiedmailsender.com/): No Georgia return addresses or Georgia-billed prepaid balances; Georgia-billed letters are fully refunded and not mailed. Recipients in Georgia are allowed. New senders can mail 3 letters in 24 hours and 10 in 30 days. - [Screening and holds](https://certifiedmailsender.com/acceptable-use): Before printing we check every letter for threats, harassment, extortion, impersonation of an agency, court or USPS, and fake legal notices; a person reviews holds. After 24 hours, unresolved holds are stopped and fully refunded. Unreadable scans/images may add a day of human review, disclosed before payment. ## Support and policies - [Support](mailto:support@certifiedmailsender.com). - [Abuse](mailto:abuse@certifiedmailsender.com): A person reviews reports within one business day; [report form](https://certifiedmailsender.com/report) also available. - [Terms of Service](https://certifiedmailsender.com/terms) - [Privacy Policy](https://certifiedmailsender.com/privacy) - [Acceptable Use Policy](https://certifiedmailsender.com/acceptable-use) - [Refund Policy](https://certifiedmailsender.com/refunds): Full refund if we do not mail; no refund once USPS accepts the letter. Unused prepaid balance is refundable on request.