How to prepare a mailed letter or fax from ChatGPT

ChatGPT can help write the letter. Preparing a physical send also needs the finished PDF, access to Postedly, a recipient and your approval of the final proof and price. Connect a custom app where your account supports it, or download the PDF and send it directly on Postedly.

See the setup guide See example requests

Connection and service lookup tested

Last tested

A private ChatGPT connection completed OAuth and successfully checked Postedly’s services. File transfer, quote, browser review and a paid send have not yet been verified in ChatGPT. A public listing is not claimed.

Client and environment
ChatGPT web, private developer-mode connection to Postedly production.
Stages completed
Private app installed; sender OAuth completed; one actual service lookup returned successfully.
Your remaining steps
Confirm ChatGPT can access the PDF or upload it through a private browser link. Prepare a quote, review its final proof and recipient on Postedly, then approve and pay through hosted Stripe Checkout.
Still unverified
Direct document transfer, quote/review flow, payment, fulfillment, refresh/disconnect and a public listing.

Use ChatGPT with Postedly

  1. Enable custom app access

    Where your account permits it, enable Developer mode in Settings → Security and login. Workspace policies may control access.

  2. Create the remote connection

    At ChatGPT Plugins, use the plus button to add a connection. Name it Postedly, add a short description, enter this public MCP URL and choose OAuth when prompted. Review the discovered tools after connecting.

    https://postedly.com/mcp/send
    Open ChatGPT’s connection setup

  3. Connect your sender account

    Continue to Postedly, verify your sender email and review the OAuth scopes. Approving this connection is separate from approving an order.

  4. Start with a service check

    In a new conversation, add the connection from the tools menu and ask which Postedly services are available. This is the stage verified in the recorded ChatGPT test.

  5. Transfer the PDF and request a quote

    Provide the final file and destination. Ask ChatGPT to upload the actual PDF or give you a private browser upload link, then prepare one quote. Open the Postedly proof yourself before approving payment.

Give it a specific request

Mail a carefully written request

First finish the wording and export the approved version as a PDF. Then make the sending request separately.

Example request
Use Postedly to prepare mailing this finished PDF to the recipient address below. Use my sender address below. Check the available mailing options, transfer the actual PDF if you can access it, and show me the final proof, recipient and total. If you cannot access the file, give me a private upload link. Do not pay or send until I approve.

Fax the PDF from your conversation

Start with a finished PDF and confirm the recipient’s US fax number. File transfer in ChatGPT remains unverified.

Example request
Use Postedly to prepare a fax of this PDF to the US number below. Check current availability and transfer the actual file, or give me a private browser upload link if you cannot. Show the final PDF including the cover page, receiving number and total. Stop before payment.

Mail a personal postcard

Finish the message and both sides of the postcard, then check the current template before preparing the PDF.

Example request
Help me finish this postcard message, check Postedly’s postcard template, and prepare a quote for the two-page PDF and recipient address I provide. Show both sides and the total, and wait for my approval before checkout.

Transfer your file

ChatGPT must be able to read the artifact’s bytes to upload it directly. A sandbox download link is not itself a Postedly upload. If the runtime cannot transfer the bytes, ask for Postedly’s private browser upload link; you do not need to paste file IDs.

  • For a letter or fax, prepare a valid, unencrypted PDF no larger than 10 MiB (10,485,760 bytes). Review the saved PDF after exporting it from the draft.
  • For mail, have the recipient’s full US postal address and your US sender address ready. For fax, confirm the receiving US fax number and your US billing address. Check the selected service’s page and layout limits before quoting.
  • Review the final proof returned with the quote, including any added cover or postal layout. An upload preview alone does not establish that the final document is ready to send.
Letter requirements Fax requirements

Mail a check

ChatGPT can prepare a paper check drawn on your own verified US checking account. The assistant never sees your account numbers and can’t sign or pay; those steps stay with you.

  1. Set up checks once, yourself

    Open Postedly’s check page in your browser, verify your email and connect your checking account. You’ll verify it with Plaid, confirm you can sign for it, set a bank passkey and save your signature.

    Set up checks

  2. Ask ChatGPT for the check

    Give the payee’s exact name and US mailing address, the amount and an optional memo. Using Postedly’s check tools, ChatGPT reads your ready accounts and drafts the check, which reserves its number and prepares a service-fee quote. Nothing is signed, charged or sent.

  3. Review, sign and pay

    Open the private review link it gives you. Check the full proof, confirm with your passkey, sign and pay the service fee. The check amount is paid from your account only when the payee deposits it.

  4. Follow the order

    ChatGPT can read the order to see when the check is printed and mailed. Postedly can’t see when it clears; your bank shows that.

Example request
Mail a $250 check to Riverside Little League, 400 Park Rd, Dayton, OH 45402, from my checking account. Memo: Spring registration. Send me the link to review and sign it.

If ChatGPT doesn’t show Postedly’s check tools, reconnect Postedly or refresh its tools, or write the check yourself on Postedly.

When a step does not work

There is no custom app or Developer mode option
Access depends on your account and workspace policy. If your workspace does not allow this connection, download the finished PDF and use Postedly’s website.
ChatGPT gives you a sandbox link or says the PDF is inaccessible
A generated-file link does not prove that the connected tool can read the file. Ask ChatGPT to transfer the exact bytes if it has access, or request a private Postedly browser upload link and choose the downloaded PDF yourself.
The connection works, but ChatGPT cannot find a tool
Open the connection in ChatGPT Plugins, refresh its metadata and start a new conversation with it enabled. First ask for Postedly’s current services; this read-only step has been tested.
ChatGPT says the letter was sent
Ask for the existing Postedly order reference and its payment and fulfillment states. Draft text, an uploaded file, a quote or a review link alone does not establish that anything was sent.

Your approval comes before the send

ChatGPT’s tool confirmation and Postedly’s order approval serve different purposes. Review the exact final proof, recipient and total on Postedly, then pay through hosted Stripe Checkout. Native ChatGPT checkout is not part of this guide.

Cancellation and refund policy

Follow the existing order

Ask the connected app for the existing order’s status, or open its Postedly order page. Check before retrying after any interrupted checkout.

Check an order on Postedly

Send directly on Postedly

You can use the finished document without connecting an assistant. Download the approved PDF, open Postedly, choose an available service and upload the file. Enter the destination and sender details, then review the final proof and full price before payment. You do not need your own printer or envelopes to mail a PDF through Postedly.

Open the sending form Follow a sending guide Check services and pricing

Before you start

  • Account and administrator settings determine custom app access. Uploads are limited to 10 MiB, with service-specific file requirements. A working MCP connection does not guarantee that a particular ChatGPT runtime can access generated or attached file bytes.

Official references

Use these platform references alongside the Postedly guide.

Ready to prepare a send?

Use the connected assistant, or finish directly with Postedly.

Start sending