The fastest way to fax from Outlook
You can send a fax through Outlook by using a fax service that integrates with your email, or by forwarding your message to a fax gateway. The most common method is to use a third-party fax service like Microsoft Fax and Scan (built into Windows), eFax, or Fax.Plus, which gives you a fax number that works like an email address. You type the recipient's fax number in the "To" field, write your message or attach a document, and send it as you would any email.
Outlook itself does not have a native fax button, but it works with fax services through email integration. This means you do not need special software or a separate fax machine — your email account becomes your fax account.
Key Takeaways
- Outlook can send faxes through third-party services that assign you a fax number and convert your email into a fax transmission.
- Microsoft Fax and Scan is free on Windows and works with Outlook; eFax and Fax.Plus are paid services with more features and reliability.
- To send a fax, you address it to the recipient's fax number formatted as an email address (for example, 5551234567@efax.com), attach your document, and send it normally.
- Most fax services charge per page sent, with costs ranging from a few cents to 25 cents per page depending on the provider.
Using Microsoft Fax and Scan on Windows
If you use Windows 10 or Windows 11, Microsoft Fax and Scan is already installed and free to use. Open the process, click "New Fax," and enter the recipient's fax number. You can type a cover page message, add attachments, and send the fax directly from the process. The fax then goes out through your internet connection.
The limitation of Fax and Scan is that it does not integrate directly into Outlook's compose window — you have to switch to the separate process. It also works best for occasional faxing rather than high volume. If you send more than a few faxes per month, a dedicated fax service is more practical.
Setting up eFax or Fax.Plus in Outlook
eFax and Fax.Plus are subscription services that assign you a dedicated fax number. Once you sign up and log into your account, you can send faxes directly from Outlook by addressing an email to the recipient's fax number in the format the service provides. For eFax, that looks like 5551234567@efax.com. For Fax.Plus, you use 5551234567@fax.plus.
Both services let you attach documents (PDF, Word, image files) and send them as faxes. The recipient receives the fax on their fax machine or email, depending on whether they have a fax number or email address. You can also receive incoming faxes through your email inbox with these services, which makes them useful if you need two-way fax communication.
eFax charges roughly 10 to 25 cents per page sent, depending on your plan. Fax.Plus pricing is similar. Both offer monthly plans starting around $10 to $15 if you send faxes regularly, or pay-as-you-go rates if you send only occasionally.
Attaching documents and sending the fax
Once your fax service is set up, sending a fax from Outlook works like sending an email. Open a new message, type the fax number in the "To" field using the format your service requires, and add a subject line if you want one. In the message body, you can type a brief note or leave it blank.
Click "Attach File" and select the document you want to fax. Most services accept PDF, Word documents (.docx), Excel files, images (JPG, PNG), and scanned documents. If you have a paper document, scan it first using your scanner or a phone app like Microsoft Lens or Adobe Scan, then attach the resulting file.
Click "Send" and the fax goes out through your fax service's network. You will usually receive a delivery confirmation email within a few minutes telling you whether the fax was sent successfully or if there was an error.
What happens if the fax number is invalid or busy
If the fax number is incorrect or the recipient's fax machine is offline, your fax service will attempt to resend the fax automatically, usually for 24 to 48 hours. You will receive a notification email if the fax fails after all retry attempts. Check the fax number and try again, or contact the recipient to confirm their fax machine is working.
Some fax services let you set up automatic retry schedules in your account settings. If you send faxes regularly to the same numbers, you can save those numbers in your Outlook contacts with the fax service's email format, so you do not have to type the full address each time.
Comparing fax services for Outlook users
| Service | Cost | How it works with Outlook | Best for |
|---|---|---|---|
| Microsoft Fax and Scan | Free | Separate process; not integrated into Outlook | Occasional faxing, Windows users only |
| eFax | $10–$25/month or pay-per-page | Send via email to fax number (5551234567@efax.com) | Regular faxing, need incoming fax capability |
| Fax.Plus | $10–$20/month or pay-per-page | Send via email to fax number (5551234567@fax.plus) | Regular faxing, international faxes |
| Google Fax (through Google Voice) | Free or low-cost | Forward email to Google Fax, then to recipient | Light faxing, Gmail users |
Frequently Asked Questions
Can I send a fax from Outlook on Mac?
Yes, but Mac does not have a built-in fax process like Windows does. You will need to use a third-party service like eFax or Fax.Plus and send the fax through email in Outlook for Mac, the same way you would on Windows. Some Mac users also use online fax portals where you upload a document and enter the fax number directly, without using Outlook at all.
What file types can I fax from Outlook?
Most fax services accept PDF, Word (.docx), Excel (.xlsx), PowerPoint (.pptx), and image files (JPG, PNG, TIFF). Some services also accept plain text files. If you have a document in another format, convert it to PDF first using your operating system's print-to-PDF feature or an online converter, then attach the PDF to your fax email.
Do I need a fax machine to receive faxes?
No. With eFax or Fax.Plus, incoming faxes arrive in your email inbox as PDF attachments. You can read them on your computer, phone, or tablet. You do not need a physical fax machine or a dedicated phone line.
How long does it take for a fax to go through?
Most faxes send within a few minutes of clicking send in Outlook. You will receive a delivery confirmation email from your fax service shortly after. If the recipient's fax machine is busy or offline, the service will retry automatically, which can take several hours or up to 48 hours depending on the service.
Can I schedule a fax to send later?
Outlook's built-in scheduling feature (Delay Delivery) works with some fax services but not all. Check your fax service's documentation to see if scheduled sending is supported. If not, you can compose the email, save it as a draft, and send it manually at the time you want it to go out.