Send a fax from email

Faxart turns email into an outbound channel: a user emails a PDF to a fax address and it goes out under their caller ID. This tutorial sends one and explains the gate that keeps it safe.

How it works

You email a PDF to {faxnumber}@your-fax-domain. The recipient fax number is the local part of the address. The broker then looks up the sender in your directory to find their fax number, which becomes the caller ID. If the sender has no fax number on file, the message is rejected. That reverse lookup is the authorization gate: a person can only send as themselves.

flowchart LR
  A[User emails PDF<br/>to 5551234 at fax domain] --> B[SMTP intake]
  B --> C{Sender has a<br/>fax number?}
  C -- no --> D[Reject]
  C -- yes --> E[PDF to TIFF<br/>send over SIP]
  E --> F[Delivery receipt<br/>back to sender]

1. Confirm the intake is reachable

The SMTP intake listens for the fax domain you configured. In production this sits behind your mail connector and is locked to its source IPs with TLS. For a local test, the intake is bound to loopback.

2. Email a PDF

Send an email to the fax address with a single PDF attached. Keep it under the configured size limit.

3. Watch it send and get a receipt

The broker converts the PDF, originates the call over SIP, and captures the result. You get a delivery or failure receipt by email, and the outbound row appears in the Sent view with its status.

Notes

• Scan-to-email devices (copiers) can be registered as intake sources by IP, so a device sends under its own caller ID without borrowing a user’s number.
• Cover sheets are prepended at send time.

Next steps

• Configuration reference for the intake and relay keys
• Add a printer to route inbound faxes to paper