How to Fax From Outlook and Microsoft 365
Outlook is an email client, not a fax line, so it cannot dial a fax number on its own. What it can do is hold the document — an attachment in a message or a file on OneDrive or SharePoint — and that document is the thing you fax. Send FAX Mail takes the PDF from your Outlook message or OneDrive, sends it to the recipient's fax number over a real fax connection, and returns a delivery receipt. The web version of Outlook and the desktop client behave a little differently, and corporate accounts add their own rules, but the underlying move is the same: get the file to PDF, then send it. A 7-day free trial covers your first pages.
What you need
- ✓An Outlook or Microsoft 365 account with the document attached or saved to OneDrive
- ✓The file as a PDF (use Save As, PDF in Word or Excel for Office documents)
- ✓A Send FAX Mail account (the 7-day free trial includes your first sends)
- ✓The recipient fax number, with country code for international faxes
How to fax from Outlook
- 1Open the Outlook message and save the attachment, or locate the file in OneDrive or SharePoint
- 2If it is a Word or Excel document, open it and use File, Save As (or Export), and choose PDF so the layout is locked
- 3Sign in to Send FAX Mail in your browser and start a new fax
- 4Upload the saved PDF, or paste a OneDrive share link into the import-from-link field to pull it in directly
- 5Enter the recipient's fax number and add a cover page if the office requires one
- 6Send and check your Outlook inbox for the confirmation that the receiving fax answered
Outlook limits worth knowing
There is no fax command inside Outlook on the web or the desktop client; the old Windows Fax and Scan was a separate program tied to a modem, not part of Outlook. Outlook attachments are generally capped at 20 MB, and larger files are pushed to OneDrive automatically, which is why importing a OneDrive link is often the smoother path. On a managed corporate account, mobile device management or data-loss-prevention rules can block downloads or restrict which sites the browser may upload to, so a work fax sometimes has to go from a personal device or an IT-approved browser.
| Aspect | On Outlook | On other platforms |
|---|---|---|
| Built-in faxing | None in Outlook — it supplies the file, not the fax | Legacy Windows Fax and Scan needed a physical modem and phone line |
| Large files | Auto-moved to OneDrive; import by share link | Gmail similarly converts big attachments to Drive links |
| Corporate restrictions | MDM/DLP policies may limit downloads and uploads | A personal Mac or phone usually has no such policy layer |
Faxing from Outlook — FAQ
No. Neither Outlook on the web nor the desktop client has a fax function — they send email. The document in your Outlook message or OneDrive is what you fax, and you send it through a fax service like Send FAX Mail by uploading the PDF or importing it from a share link.
Windows Fax and Scan is a separate utility that required a dial-up fax modem plugged into a phone line, and it was never part of Outlook. Most computers no longer have a modem, so an online fax that works from any browser has replaced it for nearly everyone.
Corporate device-management and data-loss-prevention policies can stop attachments from being saved or sites from receiving uploads. Ask IT whether the file may be sent, then either use an approved browser, import it by OneDrive link if that is permitted, or send from a personal device that holds the document.
Convert it to PDF using File, Save As, PDF before sending. A faxed Word file can shift its fonts and margins on a different machine, but a PDF is a fixed page, so the recipient's copy matches your original exactly, including any signature block.
Yes. Generate a share link in OneDrive and paste it into the import-from-link field, and the document is fetched and faxed without a manual download. This is handy for the large files Outlook automatically stores in OneDrive rather than attaching.
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