Email to Fax — Send a Fax From Your Email Client
Email to fax lets you send a fax without opening a fax app at all: you attach the document to an ordinary email, address it to an alias that encodes the destination fax number, and the message goes out as a fax. Send FAX Mail validates the sender and then runs the same send pipeline the dashboard uses, so quota, HIPAA, and number rules apply identically. There is no plugin to install — it works in any client that can send an attachment, on a desktop or a phone. The one requirement is on the operator side: email-to-fax only runs when the operator has configured an inbound-email domain and secret, so confirm it is enabled on your deployment before relying on it. To go the other direction and receive faxes in your inbox, see fax to email.
Plan requirement
Email-to-fax runs on paid plans and enforces the same page quota and HIPAA rules as any other send. It is not part of the free trial's send-only shared number in the same way — it depends on the operator having configured the inbound-email domain (INBOUND_FAX_DOMAIN) and webhook secret; when those are unset the whole feature no-ops.
How it works
Your mail provider forwards each message to a webhook the operator wired up, and that POST is secret-gated so only your configured provider can trigger a send. The alias you send to encodes the recipient fax number, and the address is tied to a per-user secret so a stranger cannot fax on your behalf. Before anything is dialed, the pure sender-auth logic checks that the alias is real, that the message passed DMARC, and that the From address is on your allowed-senders list; a message that fails any of those is dropped silently rather than bounced, so an attacker gets no feedback. Valid mail then runs through the same gated pipeline as compose, so BAA, quota, and number rules all apply, and the attachment is normalized to a fax-ready PDF.
What you can do
- ✓Send a fax by emailing an attachment to an alias that encodes the destination number
- ✓Work from any email client — desktop, webmail, or phone — with no plugin
- ✓Restrict who can send by maintaining an allowed-senders list per account
- ✓Rely on DMARC + a per-user secret alias so unknown senders are silently dropped
- ✓Run the same BAA, quota, and number gates as a dashboard send
- ✓Manage your alias and allowed senders at /dashboard/settings
Setup steps
- 1Confirm the operator has configured the inbound-email domain and secret, or the feature is off
- 2Open /dashboard/settings and note your inbound alias and add each address you will send from to allowed senders
- 3Compose an email to <alias>.<number>@ the configured inbound domain
- 4Attach the document you want faxed as a PDF, image, or supported Office file
- 5Send the email from an address on your allowed-senders list that passes DMARC
- 6Watch the fax appear in /dashboard/history, where quota and status are tracked like any send
Example
To: you-secret-alias.15551234567@fax.yourdomain.com
From: billing@yourcompany.com (on your allowed-senders list)
Subject: Invoice 4021
Attachment: invoice-4021.pdfEmail to Fax — FAQ
They are opposite directions on the same line. Email to fax is outbound — this page — where a message you compose leaves as a fax to a machine somewhere else. Fax to email is inbound: someone dials the number you own and the transmission reaches you as a PDF in your inbox. Sending works from the trial onward, while receiving needs a dedicated number and therefore a paid plan, so check which direction you actually need before choosing.
No. Email-to-fax is not a plugin or an add-in; it works in any client that can send an email with an attachment, because the conversion happens on our side after your mail provider forwards the message. You address the message to the alias and attach the document — that is the whole client-side step.
Three checks run before any dial. The alias carries a per-user secret so it is not guessable, the message must pass DMARC, and the From address must be on your allowed-senders list. A message that fails any check is dropped without a bounce, so a would-be spoofer gets no confirmation that the alias even exists.
It depends on operator configuration. The feature only runs when the deployment has set the inbound-email domain and the webhook secret; with either unset the whole path no-ops. If sending to your alias does nothing, confirm with your operator that email-to-fax is turned on before troubleshooting your mail client.
Yes. A valid email runs the same gated send pipeline as the compose form, so the pages count toward your monthly allowance and the BAA and provisioned-number gates apply. Reaching your plan's monthly page limit blocks further emailed sends with an upgrade prompt, exactly as it would in the dashboard.
Build with the Email to Fax
API access and webhooks are included on the Business and Enterprise plans. Create a key at /dashboard/developers and start sending.
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