By David Thompson ยท Published April 3, 2026 ยท Updated September 18, 2026 ยท 8 min read
Quick answer: You cannot fax directly to a raw email address โ but with an online fax service, your document lands as a PDF in the recipient's inbox in under two minutes. The recipient needs a virtual fax number; you dial it; the service handles the conversion.
Someone asks you to fax documents to their email. Or you need to send a fax and you only have an email address. Either way, faxing to an email address is entirely doable โ it just requires a small piece of infrastructure in the middle.
This guide walks you through three methods for faxing to an email address, from the quickest (a mobile app) to the most flexible (an email gateway), with exact steps for each.
What You Need Before You Start
Before picking a method, confirm one thing: does the recipient have a virtual fax number?
A virtual fax number is a regular-looking phone number (e.g., +1 212-555-0100) assigned by an online fax service. When you fax that number, the service converts the transmission into a PDF and sends it to the recipient's linked email inbox. Without a virtual fax number, the recipient's email inbox cannot accept faxes.
If the recipient doesn't have one yet, send them this: they can get a virtual number from mFax.to in under five minutes.
You always need a fax number
You cannot type someone's @gmail.com or @outlook.com address into a fax machine or fax app. You always dial a fax number โ the service bridges the gap between the phone network and the email inbox behind the scenes.
Method 1: Send via Online Fax App (Fastest)
The easiest way to fax to an email address is through a mobile fax app like mFax.to. No fax machine, no phone line โ just upload your document and send.
Download mFax or Open the Web App
On your phone, download the mFax app from the App Store or Google Play. On a computer, go to mfax.to or install mFax for Windows. Creating an account takes under two minutes โ no credit card required to start.
Tap New Fax
In the app, tap Send Fax. In the web dashboard, click New Fax. You'll be taken to the compose screen.
Enter the Recipient's Virtual Fax Number
Type the fax number exactly as given โ include the country code for international recipients (e.g., +44 for the UK, +1 for the US). This is a phone number, not an email address. The virtual number is what routes the fax to the recipient's inbox.
Attach Your Document
Tap Add Document and upload your file. mFax accepts PDF, DOCX, JPG, PNG, and TIFF. PDF is recommended for consistent formatting. You can attach multiple files โ they'll be combined into a single fax. Add an optional free fax cover sheet on the first page.
Send and Receive Confirmation
Tap Send. mFax transmits your document to the recipient's virtual fax number. Within seconds, the service converts it to a PDF and delivers it to their email inbox. You receive a delivery confirmation notification with a timestamp and page count.
Method 2: Send from Gmail or Outlook (Email Gateway)
If you prefer to work entirely from your email client, most online fax services offer an email-to-fax gateway โ a special email domain that routes your outgoing email through the fax network.
Gateway format:
[recipient-fax-number]@[provider-gateway-domain]
mFax example:
12125550100@send.mfax.to
No dashes, no spaces, no parentheses โ just the digits and the domain.
How to Fax to an Email Address from Gmail
Send From the Address You Sign In With
Email-to-fax on mFax comes with mFax Business. The email address you sign in to mFax with is authorized automatically โ there is nothing to set up. Each member of your organization faxes from their own login address; to let a colleague fax by email, invite them to the organization. Mail from any other address is not faxed.
Compose a New Email
Open Gmail and click Compose. In the To field, enter the recipient's fax number followed by @send.mfax.to โ for example: 12125550100@send.mfax.to.
Add Subject and Body (Optional)
The subject line becomes the cover page subject. The body text appears on the cover page. Both are optional โ if you omit them, mFax sends the attachment without a cover page.
Attach Your Document
Click the paperclip icon and attach your file. PDF is the most reliable format; Word, Excel, PowerPoint and images are converted automatically (up to 60 pages per fax, 20 MB per file). If you prefer, convert first with our free document converter.
Click Send
Hit Send. Gmail routes your email to the mFax gateway. The service converts your attachment into a fax transmission, delivers it to the recipient's virtual fax number, and forwards the PDF to their email inbox. You'll receive a status email confirming success or failure, and the fax appears in your organization's history in the app.
How to Fax to an Email Address from Outlook
The process is identical in Outlook or any other email client:
- Open Outlook and click New Email (from the address you sign in to mFax with).
- In the To field, enter
[faxnumber]@send.mfax.to. - Optionally add a subject and body for the cover page.
- Attach your PDF document.
- Click Send.
Works with any email client
Gmail, Outlook, Apple Mail, Yahoo Mail, Thunderbird โ any email client that can send attachments works with the fax gateway. The gateway recognizes the address you sign in to mFax with and routes the fax accordingly.
Method 3: Forward Faxes from a Physical Fax Machine
If your office uses a traditional or multifunction fax machine, many models support built-in fax-to-email forwarding โ no subscription required.
| What you need | How it works |
|---|---|
| Multifunction printer with fax | HP, Xerox, Canon, Ricoh, Brother business MFPs |
| Internal SMTP server or relay | The machine sends the PDF via your company's email server |
| Destination email address | Any inbox โ recipient receives a PDF attachment |
General setup steps (varies by model):
- On the machine's touchscreen, go to Fax Settings โ Fax Forwarding or Scan to Email.
- Enter the destination email address.
- Save the settings.
- When a fax arrives on the phone line, the machine auto-converts it to PDF and emails it to the configured address.
Check your printer's manual for the exact menu path. For organizations replacing physical machines entirely, mFax Business eliminates the hardware dependency and adds HIPAA compliance, audit logs, and team accounts.
What If You Only Have Someone's Email Address?
This is the most common source of confusion. Someone says "just fax it to john@company.com" โ but you can't dial an email address. If you're still unsure whether you can fax something through email, that guide explains exactly how the bridge works.
Here's what to do:
- Ask for their fax number โ every virtual fax account has a dedicated number. Ask: "What is your virtual fax number?"
- If they don't have one โ they'll need to create a free account with an online fax service and share the number with you. Setup takes under five minutes at mFax.to.
- If fax is optional โ consider using our free document converter to export as PDF and send it directly as an email attachment. Not technically a fax, but delivers the same file.
Quick test
Not sure if the recipient has a virtual fax number? Ask them to check their email for a confirmation from a fax service. If they have one, the number will be in the welcome email. If not, they need to sign up first.
Which Method Should You Use?
Online Fax App
Best for most people. Send from your phone or browser in under 2 minutes. No technical setup. Works anywhere.
Email Gateway
Best if you live in your email client. Compose, attach, send โ no separate app to open. Comes with mFax Business.
Fax Machine Forwarding
Best for offices with existing hardware. Built into many multifunction printers โ no monthly fee, but needs IT setup.
For individuals and small businesses, Method 1 (mFax app) is the fastest path. For teams on mFax Business who send faxes daily from Gmail or Outlook, Method 2 (email gateway) integrates seamlessly into existing workflows. For enterprise environments with physical fax infrastructure, Method 3 avoids any additional subscriptions.
Supported File Formats
| Format | Supported | Notes |
|---|---|---|
| โ Yes | Recommended โ best formatting consistency | |
| DOCX / DOC | โ Yes | Automatically converted to PDF before sending |
| JPG / PNG | โ Yes | Works well for single-page documents and photos |
| TIFF | โ Yes | Native fax format; excellent quality |
| XLSX | โ Most services | Minor formatting variation possible |
| PPTX | โ ๏ธ Some services | Verify support before sending |
If your file is not a PDF, convert it first with the free document converter at mFax.to. For multi-page documents, use the merge PDF tool to combine them before sending.
Troubleshooting Common Problems
Fax failed โ "number not found" error Double-check the recipient's virtual fax number. Confirm the country code is included for international numbers. Ask the recipient to verify their number hasn't changed.
Email gateway rejected your message mFax only accepts faxes from the email address you sign in with. Resend from that address โ or, if a colleague needs to fax by email, invite them to your organization so their own login address is authorized.
Recipient says they didn't receive the fax Check your status email. If it shows "delivered," ask the recipient to check their spam folder โ automated PDF attachments sometimes trigger spam filters. If the confirmation shows "failed," review the fax number and retry.
Document sent but content is garbled or cut off Convert to PDF before sending. Word documents and images can lose formatting during conversion. For technical documents, use PDF with embedded fonts.
Fax is too large to send Compress your PDF first with the free optimize PDF tool. Most fax services have a file size limit of 20โ50 MB per transmission.
How to Receive Faxes in Your Email (For the Recipient)
If you want incoming faxes delivered to your own email inbox, here's the setup:
- Go to mFax.to and create a free account.
- Choose a virtual fax number โ pick any area code.
- In account settings, link your email address to the number.
- Share your virtual fax number with anyone who needs to send you documents.
Every fax sent to your number is automatically converted to a PDF and delivered to your inbox. For the full walkthrough, see our guide on how to receive faxes online.
Send Your Fax Now
Faxing to an email address comes down to one key fact: the fax number is the bridge. Dial the recipient's virtual fax number, and the service delivers a PDF to their inbox โ no fax machine required on either end.
Try mFax.to free โ upload your document, enter the fax number, and send. Delivery in under two minutes, with a confirmation receipt. Over 5 million users send faxes this way every day.
For businesses needing HIPAA compliance, dedicated virtual numbers, and team accounts, mFax Business starts at about $9/mo (billed annually) โ and instead of locking you into rigid tiers, you build your own plan with a live calculator, picking the exact seats and pages you need and paying only for what you use.