By Sarah Martinez · Published April 2, 2025 · Updated June 8, 2026 · 8 min read
Quick Answer: You cannot fax directly to someone's email address from a traditional fax machine — but with an online fax service, your fax arrives as a PDF in the recipient's inbox. The process works in both directions: send a fax using an email client, or receive faxes as email attachments. mFax.to is the simplest way to get started.
You want to send a fax, but the person gave you an email address instead of a fax number. Or maybe someone told you to "fax it to their email." It sounds contradictory — fax and email are entirely different technologies. So can you actually fax to an email address?
Yes — but not in the way you might expect. Fax signals travel over phone lines; they can't reach an email inbox directly. An intermediary service does the converting. This guide explains exactly how faxing to an email address works, the two main methods for doing it, and which services make it effortless in 2026. (If you just want the plain-English answer to can you fax something through email, that companion guide covers the sending side in depth.)
Can You Fax Directly to an Email Address?
No. Traditional fax machines transmit over the public switched telephone network (PSTN) using a protocol called T.30. Email uses entirely different infrastructure — SMTP servers and the internet. There is no direct path from a fax machine to an @gmail.com or @outlook.com address.
However, the gap is easily bridged by online fax services. These services sit in the middle:
- They accept incoming fax transmissions (over the phone network)
- They convert the fax signal into a PDF file
- They deliver the PDF to an email address
The result? The recipient gets your fax as an email attachment — even if you sent it from a traditional fax machine. The sender never needs to know how the plumbing works.
The Key Requirement
For a fax to reach someone's email inbox, the recipient must have a virtual fax number from an online fax service. Their virtual number is what you dial. The service does the conversion and forwards the PDF to their email. If they only have an email address and no virtual fax number, they cannot receive faxes by email.
How Faxing to an Email Address Works
Here is the complete flow, from the moment you send to the moment the recipient opens your document:
- You dial the recipient's virtual fax number — this looks like any standard fax number (e.g., +1 212-555-0100). The recipient obtained it from an online fax service.
- Your fax transmission routes to the provider's servers — instead of going to a physical fax machine, it reaches the fax service's data center over the phone network.
- The server converts the T.30 signal into a PDF — the fax image data is decoded and packaged into a PDF file.
- The PDF is emailed to the recipient's address — the fax service sends an automated email to the email address the recipient linked to their virtual number.
- The recipient opens the PDF in their inbox — it arrives like any email attachment in Gmail, Outlook, Yahoo Mail, or any other client.
The entire process typically takes 30–90 seconds from the moment you press Send on the fax machine.
Two-Way Traffic
The same infrastructure works in reverse. If you have an online fax account, you can send faxes from your email client — compose an email, address it to [faxnumber]@provider.com, attach your document, and the service converts your email into a fax and delivers it to the recipient's fax machine. More on this in Method 2 below.
Method 1: Send a Fax Using an Online Fax App (Easiest)
The fastest way to fax to an email address is through an online fax service like mFax.to. You do not need a fax machine, a phone line, or any special hardware. The service handles everything.
This method works when:
- You want to send documents from your phone or computer
- You want confirmation of delivery
- The recipient has given you their virtual fax number
Create a Free mFax Account
Go to mFax.to or download the mFax app on iOS or Android. Sign up takes under two minutes — no credit card required to start.
Start a New Fax
Tap Send Fax in the app or click New Fax in the web dashboard. You will be prompted to enter the recipient's fax number and upload your document.
Enter the Recipient's Virtual Fax Number
Type the recipient's fax number exactly as given — include the country code for international numbers (e.g., +44 for UK). This is the number linked to their email inbox. You are dialing a fax number, not typing an email address.
Attach Your Document
Upload the file you want to send. mFax supports PDF, DOCX, JPG, PNG, TIFF, and other common formats. PDF is recommended for consistent formatting. You can also add a fax cover sheet as the first page.
Send and Confirm
Click Send. mFax transmits your document to the recipient's virtual fax number. The service converts it to a PDF and delivers it to their email inbox. You receive a delivery confirmation with a timestamp.
What If You Only Have an Email Address?
If someone gives you their email address and says "just fax it here," they likely have a virtual fax service that converts incoming faxes to email. Ask them for their fax number — every virtual fax account has one. You cannot enter a raw email address into a fax machine or fax app. You always send to a fax number; the service handles the rest.
Method 2: Send a Fax from Your Email Client (Gmail or Outlook)
Most online fax services provide an email-to-fax gateway — a special domain address that routes your email through their fax network. You send an ordinary email from Gmail or Outlook, and it arrives as a fax at the recipient's machine or email inbox.
Format:
[recipient-fax-number]@[provider-gateway-domain]
Example for mFax:
15551234567@send.mfax.io
No dashes, no spaces, no parentheses — just the digits followed by the gateway domain.
Step-by-Step: Email-to-Fax from Gmail
- Open Gmail and click Compose.
- In the To field, enter the recipient's fax number + gateway domain (e.g.,
12125550100@send.mfax.io). - In the Subject line, you can enter the recipient's name or a reference — some services use this as the cover sheet subject.
- In the Body, write your cover message (optional — this appears as a cover page).
- Click Attach and upload your document (PDF recommended).
- Click Send. The fax service intercepts the email, converts the attachment to a fax, and delivers it.
Step-by-Step: Email-to-Fax from Outlook
The process is identical in Outlook:
- Click New Email.
- Enter
[faxnumber]@[gateway-domain]in the To field. - Attach your document and add an optional body message.
- Click Send.
Which Email Account Can You Use?
Any email address registered with your fax provider can send faxes through the gateway. Most services tie the sending permission to your registered email — if you send from an unregistered address, the email is rejected. Check your fax account settings to confirm which email address is authorized.
What the Recipient Needs to Receive a Fax by Email
For your fax to land in someone's email inbox, the recipient must:
- Have a virtual fax number — obtained from an online fax service (mFax, eFax, Fax.Plus, RingCentral Fax, etc.)
- Link their email address to that number — they configure this in their fax account settings. Any fax sent to their number is automatically forwarded to their inbox as a PDF.
- Share that fax number with you — you need the number to dial it. They cannot give you their @gmail.com address and expect a fax to arrive there directly.
If the recipient does not have a virtual fax number, they will need to set up fax-to-email before they can receive faxes electronically. The entire setup takes under five minutes.
Best Services for Faxing to an Email Address
| Service | Email Gateway Format | Starting Price | HIPAA | Best For |
|---|---|---|---|---|
| mFax.to | number@send.mfax.io | Pay-per-fax or from $9/mo | Business plan | Individuals & small business |
| eFax | number@efaxsend.com | From $18.95/mo | Yes | Enterprise & healthcare |
| Fax.Plus | number@fax.plus | Free tier / from $6.99/mo | Yes | Light users & startups |
| MyFax | number@myfax.com | From $12/mo | Yes | Small business teams |
| RingCentral Fax | number@rcfax.com | Bundled with RingCentral | Yes | Existing RingCentral users |
mFax.to stands out for its mobile-first design and pay-per-fax flexibility — no monthly commitment required. With a 4.8 App Store rating and over 5 million users, it is the easiest entry point for anyone who needs to fax occasionally without a subscription. For teams needing HIPAA-compliant faxing, mFax Business plans include encryption, audit trails, and BAA signing starting at about $9/mo (billed annually) — and rather than forcing you into fixed tiers, you build your own plan, picking the exact number of seats and pages you need.
File Formats You Can Fax to an Email Address
| Format | Supported? | Notes |
|---|---|---|
| ✅ Yes | Recommended. Best formatting consistency | |
| DOCX / DOC | ✅ Yes | Converted to PDF before sending |
| JPG / PNG | ✅ Yes | Images fax fine; use PDF for multi-page docs |
| TIFF | ✅ Yes | Native fax format; widely supported |
| XLSX / XLS | ✅ Most services | May have formatting variation |
| PPTX | ⚠️ Some services | Check provider support before sending |
| Scanned paper | ✅ Yes | Scan to PDF first for best quality |
If your document is not already a PDF, use our free document converter to convert Word files, images, and other formats before faxing. Multi-page documents should be combined into a single PDF using our free merge PDF tool before sending.
Common Mistakes to Avoid
1. Entering the email address instead of a fax number You always send to a fax number — not to an @gmail.com or @outlook.com address. If someone only gives you an email address, ask for their virtual fax number.
2. Wrong email gateway format
Omit all dashes, spaces, and parentheses from the fax number when using an email gateway. 1-212-555-0100@send.mfax.io will fail; 12125550100@send.mfax.io will work.
3. Sending from an unauthorized email address Most services only allow faxes from your registered email. If you send from a different address, the fax is rejected silently. Check your account settings.
4. Forgetting the country code for international faxes When faxing internationally, include the full country code (e.g., 1 for the US, 44 for the UK). For international faxing best practices, see our complete international fax guide.
5. Attaching unsupported file types Stick to PDF, DOCX, JPG, or TIFF. Attaching an HTML file or a ZIP archive will cause the fax to fail.
How to Receive Faxes in Your Email (For the Recipient)
If you are the one who wants to receive faxes in your email inbox, the setup is straightforward:
- Sign up for an online fax service like mFax.to
- Get a virtual fax number (choose a local area code)
- Link your email address in account settings
- Share your virtual fax number — anyone who dials it will have their fax delivered to your inbox as a PDF
For a detailed walkthrough of the receiving side, see our guide on how to receive faxes online.
Send Your First Fax Now
Faxing to an email address is not complicated once you understand that the fax number is the bridge between the two worlds. The recipient gets a virtual fax number; you dial it; the service delivers a PDF to their inbox.
Try mFax.to — upload your document, enter the fax number, and send in under two minutes. No hardware, no phone line, no waiting. Over 5 million users send faxes this way every day.
For business teams that need HIPAA compliance, audit logs, and dedicated virtual numbers, mFax Business starts at about $9/mo — fully customizable, so you build your own plan and pay only for the seats and pages you actually use.