Fax from Outlook — Email to Fax
You can fax from Outlook using our email-to-fax feature — with no Outlook add-in and no desktop connector. You write a normal message in Outlook, attach your document, and send it to an alias that encodes the destination fax number. Our inbound-email handler authenticates the sender and runs the same send pipeline the dashboard uses. The prerequisite is on the operator side: email-to-fax runs only when the operator has configured an inbound-email domain and secret, so confirm it is enabled on your deployment before relying on it from Outlook or Microsoft 365 mail.
Plan requirement
Faxing from Outlook via email-to-fax works on paid plans and enforces the same page quota and HIPAA rules as any send. It depends on the operator having set the inbound-email domain (INBOUND_FAX_DOMAIN) and webhook secret; when either is unset the feature no-ops regardless of plan.
How it works
Outlook hands your message to Microsoft 365 (or Exchange), which forwards it to a secret-gated webhook the operator configured. The alias encodes the recipient number and carries your per-user secret, so it cannot be guessed. Before any dial, our sender-auth logic verifies the alias is real, the message passed DMARC — Microsoft 365 signs outbound mail so it does — and the From address is on your allowed-senders list. Anything failing a check is dropped silently, not bounced, to avoid backscatter. A valid message runs the shared gated pipeline, so BAA, quota, and number rules all apply, and your Outlook attachment is normalized to a fax-ready PDF before it goes out.
What you can do
- ✓Send a fax from Outlook by attaching a file and addressing it to your fax alias
- ✓Work in Outlook desktop, Outlook on the web, or the mobile app with no add-in
- ✓Restrict sending to approved Outlook addresses via your allowed-senders list
- ✓Lean on Microsoft 365's DMARC and your secret alias so spoofed mail is 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, note your alias, and add your Outlook address to allowed senders
- 3In Outlook, compose a new message to <alias>.<number>@ the configured inbound domain
- 4Attach the document as a PDF, image, or supported Office file
- 5Send from the Outlook address you added to allowed senders
- 6Confirm the fax in /dashboard/history, where quota and status are tracked
Example
# In Outlook
To: you-secret-alias.15551234567@fax.yourdomain.com
Subject: Purchase order
Attach: po-8842.pdfOutlook — FAQ
No. Nothing installs into Outlook. Email-to-fax converts the message on our side after Microsoft 365 forwards it, so Outlook desktop, web, and mobile can all fax by attaching a file and addressing the message to your alias — no add-in, ribbon button, or COM connector involved.
Microsoft 365 signs and aligns its outbound mail so it passes DMARC, which is one of the three checks we require alongside a real alias and an allowed From address. The step you control is adding the exact Outlook address you send from to your allowed-senders list; the DMARC part is handled by Microsoft by default.
Usually because email-to-fax is not enabled on the deployment. It only runs when the operator has configured the inbound-email domain and secret; with either unset the whole path no-ops. Verify with your operator that the feature is on, then confirm your Outlook address is on the allowed-senders list.
Yes. A valid Outlook message runs the same gated pipeline as compose, 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 sends from Outlook with an upgrade prompt.
Build with the Outlook
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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