The basic method: email-to-fax gateways

You can send a fax using email by routing your message through a fax gateway service. These services convert your email into a fax and deliver it to a standard fax machine on the other end. The recipient sees a normal fax transmission — they do not receive an email.

The process is straightforward: you compose an email to a special fax number address (formatted like 5551234567@faxgateway.com), attach your document, and send it. The gateway converts the attachment to fax format and dials the recipient's fax machine. Most gateways deliver within minutes.

This method works because fax machines and email systems can exchange data through intermediary services. You need three things: an email account, a document to send (usually a PDF or image file), and the recipient's fax number. The gateway handles the rest.

Key Takeaways

  • Email-to-fax gateways convert your email attachment into a fax transmission and send it to a standard fax machine.
  • You address the email to a special fax number format (like 5551234567@faxgateway.com) rather than a person's name.
  • Most gateways charge per fax or offer monthly plans, though some include a limited number of free faxes per month.
  • The recipient receives a standard fax on their machine — they do not get an email or need special software.
  • Delivery typically takes a few minutes, but some services queue faxes during off-hours or if the line is busy.

Popular fax gateway services and how they work

Several established services offer email-to-fax conversion. eFax lets you send faxes from your email inbox and also receive faxes as email attachments. You get a dedicated fax number, and the service stores your fax history online. Pricing runs from about $10 to $20 per month depending on how many faxes you send.

Fax.plus works similarly — you send an email to a fax number address, and the service converts it. It offers a free tier with a limited number of faxes per month, or paid plans for higher volume. HelloFax integrates with document-signing software and works well if you need to sign and fax contracts.

Google Fax is available through Google Workspace (formerly G Suite) and lets you send faxes directly from Gmail. If your workplace uses Google Workspace, this may already be included in your account. Microsoft 365 offers similar fax integration for business subscribers.

Smaller services like Fax Burner and MyFax also exist. The main differences between services are pricing structure, storage limits, and whether they offer a dedicated fax number for receiving faxes back. Compare based on how many faxes you send per month and whether you need to receive faxes as well.

Step-by-step: sending your first fax via email

Start by choosing a gateway service and creating an account. Most services ask for your email address, a password, and payment information (even if you use a free tier). Some require you to verify your email address by clicking a link they send you.

Once your account is active, you will receive instructions on how to format the fax number address. For example, if you want to send a fax to 555-123-4567, you might email it to 5551234567@efax.com or 5551234567@faxplus.com — the exact format depends on the service. Write this address down or save it as a contact.

Open your email and create a new message. Address it to the fax number in the format your service specifies. Leave the subject line blank or write something brief — most fax machines do not display email subject lines. Attach your document (PDF, Word, image file, or other supported format). Write any cover sheet information in the email body if needed, though many services generate a cover sheet automatically.

Send the email. The gateway receives it, converts the attachment to fax format, and dials the recipient's fax machine. You will usually get a confirmation email within a few minutes saying the fax was sent successfully or failed. If it failed, the confirmation tells you why — usually a busy line or invalid number — and most services let you resend for free.

Document formats that work best

PDF files are the most reliable format for fax transmission. They preserve formatting, fonts, and images consistently across different fax machines. If you have a Word document, scan it to PDF or export it as PDF before sending.

Image files (JPG, PNG, TIFF) also work, but they may not compress as efficiently, which can slow delivery or increase file size charges. If you are faxing a scanned paper document, TIFF format is standard in the fax industry and usually produces the clearest result.

Avoid sending faxes in formats like Excel spreadsheets or PowerPoint presentations without converting them first. Fax machines expect single-page or multi-page documents, not interactive files. Most gateways will reject these formats or convert them unpredictably.

File size matters with some services. A typical page of text becomes a 50 to 100 KB fax file. If you are sending many pages or high-resolution images, check your service's file size limit — usually 10 to 25 MB per fax. Compress large PDFs or split them into multiple faxes if needed.

Pricing and what to expect

Fax gateway pricing varies widely. Some services charge per fax (typically $0.50 to $2 per page), while others charge a monthly subscription. A basic monthly plan might cost $10 to $15 and include 50 to 100 outgoing faxes. Higher-volume plans cost more but lower the per-fax cost.

Free services exist but usually limit you to a few faxes per month or require you to view ads. If you send faxes rarely — a few times a year — a free tier or pay-per-fax model makes sense. If you send faxes regularly, a monthly subscription is cheaper overall.

Some services bundle fax with other features. If you already pay for Google Workspace or Microsoft 365, fax may be included, so check your account settings before paying for a separate service. Employer-provided fax services are also common — ask your IT department whether your company has a fax gateway you can use.

When email-to-fax does not work

Fax machines that are offline or have a busy signal will cause delivery to fail. Most gateways retry automatically a few times over several hours. If a fax fails after retries, you will get a notification, and you can try again later or call the recipient to confirm their fax machine is working.

International faxes may take longer or cost more. Some gateways charge extra for faxes sent outside the United States. Check your service's pricing before sending to another country.

Very old fax machines or those with unusual settings sometimes reject incoming faxes from gateways. If this happens, ask the recipient to check their machine's settings or try calling their fax line to confirm it is receiving. In rare cases, you may need to use a traditional fax machine or ask the recipient to provide an email address instead.

Frequently Asked Questions

Can the recipient reply to my fax via email?

Not directly. A fax machine produces a paper output, not an email. However, some gateway services let you receive faxes as email attachments. If both you and the recipient use the same service, they can send a fax back to your email address, and you will receive it as an attachment. Otherwise, they would need to scan their reply and email it to you separately.

What if I do not have a PDF or need to fax a handwritten document?

Scan the document using a scanner or smartphone app (many phones have built-in scanning in the camera app or Notes app). Save it as a PDF or image file, then attach it to your email. The quality depends on your scan — use good lighting and hold the document flat for the clearest result.

Is sending a fax via email find?

Email-to-fax gateways use encryption to protect your message in transit, similar to regular email. However, the fax itself is printed on paper at the recipient's machine, so physical security depends on who has access to their fax machine. If you are sending sensitive information, confirm the recipient will be present to collect the fax when ready.

Can I schedule a fax to send at a specific time?

Some gateway services offer scheduling, but not all. Check your service's features — if available, you can usually set a date and time, and the gateway will send the fax then. This is useful if you want to send a fax during business hours or avoid peak times when fax lines are busy.

What happens if my fax is too large to send?

Most services have a file size limit (typically 10 to 25 MB). If your fax exceeds this, compress the PDF, reduce image resolution, or split the document into multiple faxes. You can also remove unnecessary pages or images to reduce file size before sending.