A registered letter gives you a record from the post. How much that record proves depends on the country and the service. This page sums it up for every service that we send. Our guides link here instead of repeating it.
| Service | Handover recorded | Delivery recorded | Signature |
|---|---|---|---|
| United States: Certified Mail with return receipt (USPS) | Yes | Yes | Yes |
| Belgium: Registered letter (bpost recommandé / aangetekend) | Yes | Yes¹ | No |
| Germany: Registered letter (Deutsche Post Einschreiben Einwurf) | Yes | Yes² | No |
| Spain: Registered letter with signature (Correos carta certificada) | Yes | Yes | Yes |
| Standard letter (all countries) | Yes | No | No |
¹ On its own, bpost’s receipt is proof of posting, not proof of delivery. We do not offer the acknowledgement of receipt yet. ² On its own, the mailbox record is not proof of delivery in a German court (Federal Labour Court, 2 AZR 184/25).
Registered letters come with a tracking number. We cannot fetch the post’s delivery receipt for you yet. Within Austria, we do not offer a registered letter yet: a letter to Austria goes as a standard letter.
Germany: Einschreiben Einwurf
Deutsche Post records the date on which the carrier reports the letter as put into the mailbox. There is no signature. Since May 2026, this record on its own gives no prima facie proof of delivery, because the carrier confirms the drop on the scanner before putting the letter in (Federal Labour Court, 7 May 2026, 2 AZR 184/25, in German). In 2025, the court already held that the posting receipt and the online tracking status are not enough (2 AZR 68/24).
You get the tracking number and a link to Deutsche Post's tracking page. We cannot get Deutsche Post's delivery receipt (Auslieferungsbeleg) for you yet.
Belgium: recommandé / aangetekend
bpost records the posting and the delivery, without a signature. bpost says that its receipt is a legally valid document in a dispute (bpost): it shows the posting. Track & Trace notices have no legal value (bpost FAQ, in French). Proof of delivery needs an acknowledgement of receipt (avis de réception). We do not offer it yet.
Spain and the United States: with signature
Correos hands the carta certificada over against the signature of the addressee or of the person who accepts it (Correos, in Spanish). USPS records the delivery of Certified Mail and the signature (USPS DMM 503). You get the tracking number. We cannot get the signed record or the return receipt for you yet.
Standard letters
We record when the post receives the letter. The post does not record the delivery. This holds for every country without a registered letter, Austria included.
What no registered letter proves
What the letter says. A record shows that a letter was posted or delivered, not its content. Save the PDF preview before you approve: it is exactly what we print. We delete the letter text when the letter reaches a final state.
Sources
Checked on 17 October 2026.
- German Federal Labour Court: 2 AZR 184/25 (7 May 2026), beck-aktuell report, 2 AZR 68/24 (30 January 2025)
- Deutsche Post: Einschreiben (in German)
- bpost: How do I send registered mail?; bpost FAQ: standard or registered (in French)
- Correos: Carta certificada (in Spanish)
- USPS Domestic Mail Manual 503
Use it with Claude, ChatGPT, Grok or Mistral Vibe
Before the launch, only invited testers can create an account. Everyone else can join the waitlist.
Add Agent Letter Desk to your AI app once, with this server URL: https://agentletterdesk.com/mcp
- Claude (claude.ai, desktop and mobile): Add to Claude opens Claude with the name and the URL filled in. Select Add, then Connect. Sign in and allow access. In a chat, select + › Connectors and turn on Agent Letter Desk. By hand: Customize › Connectors › + Add › Add custom connector, then paste the URL.
- ChatGPT (chatgpt.com): copy the URL and open ChatGPT. Plugins › Add › Add custom MCP server. Paste the URL, choose OAuth, sign in and allow access. Worked on the Free plan when we checked (13 October 2026). OpenAI decides which plans can add one.
- Grok (grok.com): copy the URL and open Grok's connectors. New connector › Custom. Enter a name and paste the URL. Sign in and allow access in the window that opens. In a chat, type @ and pick Agent Letter Desk (Grok uses a connector only when you select it).
- Mistral Vibe (chat.mistral.ai, formerly Le Chat): copy the URL and open Mistral Vibe's connectors. + Add Connector › Custom MCP Connector. Enter a name without spaces, such as AgentLetterDesk, and paste the URL. Sign in and allow access. In a chat, select + › Connectors › Agent Letter Desk (without this step, Mistral Vibe may write the letter itself). Works on the free plan.
You sign in with your e-mail address or your Google account. Then ask your AI for the letter. You check the preview and the price. Nothing goes out without your yes.
Prices, destinations and the rules for every letter: All prices and destinations · How it works · Safeguards · Terms · Full facts for AI agents