To fax from Outlook, you need an account with an online fax service. Compose a new email, enter the recipient’s fax number followed by your provider’s sending domain in the To field (for example, [email protected]), attach your document as a PDF, and click Send. The fax service converts the email into a fax and transmits it to the recipient’s fax machine. No fax machine or phone line required.
How to Send a Fax from Outlook: Step-by-Step
Step 1: Sign Up for an Online Fax Service
You need a fax service that supports email-to-fax delivery. When you sign up, the service gives you a sending domain — this is what goes after the @ symbol when you address your fax email. The main options compatible with Outlook:
| Service | Sending domain | Starting price | Notes |
|---|---|---|---|
| RingCentral | @rcfax.com | ~$17.99/mo | Strong Microsoft 365 integration |
| eFax | @efaxsend.com | ~$18.99/mo | Reliable, widely used |
| MyFax | @myfax.com | ~$12/mo | Good international coverage |
| HelloFax | @hellofax.com | ~$9.99/mo | 5 free pages/month on free tier |
After signing up, note the sending domain from your welcome email. You will use it every time you send a fax from Outlook.
Step 2: Prepare Your Document
Save your document as a PDF before sending. Word and Excel files are technically supported by most providers, but PDF is safer — it preserves fonts, margins, and layout during the fax conversion. Use File > Print > Microsoft Print to PDF (or Save As PDF) to create the file.
Step 3: Compose the Email in Outlook
Open Outlook — desktop app, Outlook.com, or the mobile app — and start a new message.
| Field | What to enter | Example |
|---|---|---|
| To | Fax number (digits only) + @ + sending domain | [email protected] |
| Subject | Cover page title (optional) | Insurance Claim — Policy #44821 |
| Body | Cover page message (optional — check provider behavior) | Please process and return signed copy by Friday. |
| Attachment | Your PDF document | insurance-claim.pdf |
Number format: Digits only — no dashes, spaces, or parentheses. Always include the country code. A U.S. number like (212) 555-1234 becomes 12125551234.
Cover page behavior varies by provider. RingCentral and eFax use the email body as cover page text. HelloFax ignores the email body and only faxes the attachment. Check your provider’s documentation if this matters for your use case.
Step 4: Send and Confirm
Click Send. Your fax service will receive the email, convert the attachment, and transmit it. Most domestic faxes deliver within 1 to 3 minutes. You will receive a confirmation email in your Outlook inbox once transmission is complete. If delivery fails, you will receive a failure notice with the reason.
Outlook-Specific Notes by Version
Outlook Desktop App (Microsoft 365 / Office)
The email-to-fax method above works with the desktop app exactly as described. One additional consideration: most fax services only process emails sent from the address registered to your account. If you have multiple email addresses configured in Outlook (such as a personal account and a work account), send the fax from the address you used when signing up with your fax provider. Emails sent from an unregistered address will be rejected.
Some Microsoft 365 business plans include RingCentral fax integration as a native add-in. If your organization has this enabled, you may see a Fax option directly in the Outlook ribbon. Ask your IT department whether this is available before signing up for a separate personal service.
Outlook.com (Web Browser)
Works the same way. Click New message, enter the fax address in the To field, attach your PDF, and send. Confirmation emails arrive in your Outlook.com inbox.
Outlook Mobile App (iPhone or Android)
Tap the compose icon, enter the fax address in the To field, tap the attachment icon to attach your PDF from Files or cloud storage, and tap Send. The fax service processes the transmission the same way regardless of whether the email was sent from desktop or mobile.
Older Outlook Versions With a Built-In Fax Wizard
Outlook 2003 and 2007 included a fax wizard under the File menu. That feature required a physical fax modem connected to your computer and a dedicated phone line — it has nothing to do with online fax services. It is also no longer supported. If you are on a current version of Outlook, ignore it. Use the email-to-fax method described above instead.
How to Receive Faxes in Outlook
When you sign up for an online fax service, you are assigned a dedicated fax number. Any fax sent to that number is converted to a PDF and delivered to your email inbox as an attachment — in this case, your Outlook inbox. No setup is required on the Outlook side. Incoming faxes arrive as regular emails with a PDF attachment.
To keep incoming faxes organized, create a folder in Outlook named “Faxes Received” and set up a rule to automatically move emails from your fax provider’s sending address into that folder. In Outlook desktop: Home > Rules > Create Rule, then filter by sender address.
Troubleshooting
No confirmation email received
Check your Junk folder — confirmation emails from fax services often trigger Outlook’s spam filter on first use. Also log in to your fax provider’s web dashboard and check the sent fax log. If the fax shows as sent there but no email arrived, add the provider’s sending address to your Outlook safe senders list.
Fax rejected or not processed
The most common cause is sending from an email address that is not registered with your fax account. Verify which address you signed up with and send from that address. Some providers support multiple authorized addresses on higher-tier plans — check your account settings.
Delivery failure: busy or no answer
The recipient’s fax line was unavailable. Most providers retry automatically 3 to 5 times. If retries fail, confirm the fax number with the recipient and try again. Check that you included the country code and used digits only with no formatting characters.
Recipient received blank or garbled pages
The PDF did not convert cleanly. Open the document in Word or another app, use File > Print > Microsoft Print to PDF to create a fresh PDF (rather than Save As), and resend. Printing to PDF flattens the file and resolves most rendering issues caused by embedded fonts or complex formatting.
Frequently Asked Questions
Can I fax directly from Outlook without a third-party service?
Not with modern versions of Outlook. The built-in fax wizard that existed in Outlook 2003 and 2007 required a physical fax modem and is no longer supported. Current versions of Outlook require an online fax service to send faxes by email.
Does Microsoft 365 include fax capabilities?
Not natively. However, some Microsoft 365 business plans include RingCentral or similar services as bundled add-ins depending on your organization’s licensing. Check with your IT department or see your Microsoft 365 admin portal under integrated apps.
Can I send a fax from a work Outlook account?
Yes, if you register your fax service account using your work email address. If you signed up with a personal email and try to send from your work address, the fax service will likely reject the email. Either register with your work address or check whether your provider supports multiple authorized senders.
What file formats does Outlook support for fax attachments?
Outlook itself has no restrictions on attachment format — the limitations come from your fax provider. Most providers support PDF, DOC, DOCX, TXT, RTF, TIFF, JPG, and PNG. PDF is recommended for anything where layout or formatting matters.
Can I send a fax to multiple recipients from Outlook?
Yes. Add each recipient’s fax address as a separate entry in the To field. For example, adding [email protected] and [email protected] will send the fax to both numbers. You will receive a separate delivery confirmation for each recipient.
Is faxing from Outlook secure?
Reputable fax services encrypt documents during transmission and storage. Outlook itself supports TLS encryption for email in transit. For healthcare or legal documents requiring HIPAA compliance, use a provider that explicitly offers a Business Associate Agreement — eFax and RingCentral both have HIPAA-compliant plans. See our HIPAA-compliant faxing guide for details.
How is faxing from Outlook different from faxing from Gmail?
The underlying process is identical — both use the same email-to-fax method with the same provider sending domains. The only difference is the email client you compose from. See our how to fax from Gmail guide if you need to send from a Gmail account instead.