By David Thompson · Published January 20, 2026 · Updated June 8, 2026 · 6 min read
Quick Answer: Outlook can't fax natively, but you can send a fax from Outlook in 3 steps using email-to-fax. Compose a new email, address it to
[fax-number]@[fax-service-domain], attach your document, and hit Send. Try it with mFax.to.
Looking to fax from Outlook without a fax machine? You're not alone — it's one of the most common questions from Microsoft 365 users. While Outlook doesn't include faxing, there's a simple workaround: email-to-fax lets you send a fax the same way you send an email.
No add-ins to install, no phone line, and no hardware. This method works with Outlook 365, classic Outlook desktop, Outlook on the web, and even the Outlook mobile app. Here's how.
Fastest Method
Skip the setup — visit mFax.to, upload your document, enter the fax number, and send in under 2 minutes. No Outlook workaround needed.
Does Outlook Have Built-in Fax?
No. Microsoft has officially confirmed that Microsoft 365 applications — including Outlook, Word, and Excel — do not include built-in faxing capabilities. The suite is designed for email and cloud collaboration, not fax transmission.
Older versions of Outlook (2003–2010) had a limited "Internet Fax" feature that connected to third-party fax providers, but Microsoft deprecated this years ago. Windows Fax and Scan still exists as a legacy tool, but it requires a physical fax modem and only works with classic Outlook — not the new Outlook or Outlook 365.
The modern solution: use email-to-fax. It works with any version of Outlook and requires nothing to install.
How to Fax from Outlook (Email-to-Fax)
This is the most reliable method. You compose a regular email in Outlook, but instead of sending it to a person's email address, you send it to a fax number through your fax service's gateway.
Sign Up for an Online Fax Service
Create an account with an online fax service like mFax. You'll get a fax gateway domain (e.g., send.mfax.to) that converts your emails into faxes.
Compose a New Email in Outlook
Open Outlook and click New Email. In the To field, enter the recipient's fax number followed by your provider's domain. For example: 15551234567@send.mfax.to — use the full number with country code.
Attach Your Document
Attach the file you want to fax. Supported formats include PDF, DOC, DOCX, XLS, XLSX, JPG, PNG, and TIFF. PDF is recommended for the best formatting.
Send and Get Confirmation
Click Send. Your fax service converts the email into a fax and transmits it to the recipient's fax machine. You'll receive a delivery confirmation email in your Outlook inbox within minutes.
What About the Email Body?
The text in your email body typically becomes the fax cover page. Include the recipient's name, your name, and a brief subject line — just as you would on a standard fax cover sheet.
What the Recipient Sees
The recipient's fax machine prints your document exactly as attached. If you sent a PDF, it prints the PDF. If you included text in the email body, it prints as a cover page before the attachment. The recipient doesn't see an email — they get a normal fax.
How to Receive Faxes in Outlook
Receiving faxes in Outlook is even easier than sending. With a virtual fax number, incoming faxes arrive as PDF attachments in your Outlook inbox — no fax machine, no phone line.
Here's how it works:
- Get a virtual fax number from a service like mFax Business
- Share your fax number with anyone who needs to send you faxes
- Receive faxes as email — each incoming fax appears as a new email with a PDF attachment in your Outlook inbox
- View, download, or forward the fax like any other email attachment
This turns Outlook into a full send-and-receive fax solution. No hardware, no paper, and every fax is automatically archived in your email.
Outlook vs. Outlook: Which Version Works?
The email-to-fax method works with every version of Outlook. However, some legacy methods only work with specific versions:
| Method | Outlook 365 | Classic Desktop | New Outlook | Outlook Web | Outlook Mobile |
|---|---|---|---|---|---|
| Email-to-fax | Yes | Yes | Yes | Yes | Yes |
| Fax add-ins | Some | Yes | No | No | No |
| Windows Fax & Scan | No | Yes | No | No | No |
Our recommendation: use email-to-fax. It's the only method that works everywhere — desktop, web, and mobile — with no compatibility issues.
Avoid Windows Fax & Scan
Windows Fax and Scan requires a physical fax modem, only works with classic Outlook (not New Outlook), and Microsoft has stopped investing in it. Unless you already have a fax modem connected to your PC, skip this method entirely.
Can I Fax from the Outlook Mobile App?
Yes. The email-to-fax method works from the Outlook mobile app on both iOS and Android. The process is identical:
- Open the Outlook app
- Tap Compose
- Address the email to
[fax-number]@[fax-service-domain] - Attach your file (you can attach from your phone's camera, Files app, or cloud storage)
- Tap Send
That said, if you're already on your phone, a dedicated fax app like mFax may be faster — you can scan a paper document with your camera, add a fax number, and send without composing an email at all.
Outlook Fax Add-ins
For organizations that send many faxes, some services offer dedicated Outlook add-ins through the Microsoft AppSource marketplace. These add-ins place a Send Fax button directly in Outlook's compose window.
Popular options include Retarus Fax for Outlook and eFax for Outlook. However, most add-ins:
- Only work with classic Outlook desktop — not New Outlook, web, or mobile
- Require admin installation in corporate environments
- Cost extra on top of the fax service subscription
For most users, the standard email-to-fax method is simpler, works everywhere, and doesn't require IT approval.
Tips for Better Faxes from Outlook
- Use PDF attachments. PDFs preserve formatting exactly. Word and Excel files may reflow when converted, causing layout issues on the recipient's end.
- Include a cover page. Type a short message in the email body — it becomes the cover page. Include your name, phone number, and page count. Or generate one with our free fax cover sheet generator.
- Double-check the fax number. Typos in the number mean your document goes to the wrong machine — or nowhere at all. Include the country code and area code.
- Keep file sizes reasonable. Most fax services accept up to 20 MB per email. If your file is larger, use our free PDF optimizer to compress it.
- Check your Sent folder. After sending, look for the delivery confirmation email. If the fax fails (wrong number, busy line), you'll get a bounce-back notification in Outlook.
For HIPAA and Business Compliance
If you're faxing patient records, legal documents, or other sensitive information from Outlook, standard email-to-fax may not meet compliance requirements. Healthcare providers need:
- TLS 1.2+ encryption on fax transmissions
- A signed Business Associate Agreement (BAA)
- Audit logging with timestamps and recipient details
- Access controls with MFA
Standard Outlook email is not encrypted end-to-end by default. For HIPAA-compliant faxing, use a service built for compliance. mFax Business includes encryption, BAA, and audit logging starting at about $9/mo (billed annually).
Fax from Outlook vs. Other Methods
| Method | Best For | Needs Hardware | Works on Mobile |
|---|---|---|---|
| Email-to-fax (Outlook) | Office workers already in Outlook | No | Yes |
| mFax app | Quick one-time faxes from phone | No | Yes |
| Fax from computer | Users without email preference | No | Desktop only |
| Physical fax machine | High-volume paper faxing | Yes (machine + phone line) | No |
| Store faxing (UPS, FedEx) | Rare one-off faxes | No (in-store) | No |
For a detailed comparison, see our guide on how to fax from a computer or our review of the best online fax services.
Send Your Fax Now
Outlook wasn't built for faxing — but with email-to-fax, it doesn't need to be. Compose an email, address it to a fax number, attach your document, and send. Done.
For personal faxing, download the mFax app — upload a PDF or snap a photo, and fax in under 2 minutes. Over 5 million users and a 4.8-star App Store rating.
For business teams, mFax Business gives you virtual fax numbers, HIPAA compliance, and a shared dashboard. Instead of rigid fixed tiers, you build your own plan — pick the exact seats and pages you need with a live calculator and pay only for what you use, from about $9/mo.
Related Guides
- How to Fax from Email: Gmail, Outlook & Yahoo — full email-to-fax walkthrough
- Fax to Email: How to Receive Faxes in Your Inbox — incoming fax setup
- How to Fax from a Computer — Windows, Mac, and online
- Fax Cover Sheet Templates — free templates
- Best Online Fax Services Compared — service comparison