The basic method: email-to-fax gateways

You send a fax from email by using an email-to-fax gateway — a service that converts your email message and attachments into a fax and delivers it to a fax machine. Instead of using a fax machine or fax software, you straightforward address an email to a special fax number in email format, and the gateway handles the rest. The recipient receives the fax on their end as if you had sent it from a traditional fax machine.

The process works because fax numbers can be converted into email addresses. A fax number like 555-123-4567 becomes something like 5551234567@faxgateway.com, depending on which service you use. You attach your document, send the email, and the gateway translates it into a fax transmission.

Most email-to-fax services are free for a limited number of faxes per month, with paid plans available if you need to send more. Some services charge per page, while others charge a flat monthly fee. A few require no account at all — you straightforward send to their gateway address and pay as you go.

Key Takeaways

  • Email-to-fax gateways convert your email into a fax by translating the fax number into an email address format, so you send from your regular email inbox.
  • Common free services include eFax, Fax.plus, and HelloFax, each offering a different number of free faxes monthly before charging.
  • You need the recipient's fax number, and your document must be in a format the gateway accepts — usually PDF, Word, or image files.
  • The fax arrives on the recipient's fax machine looking like a standard fax, with no indication it came from email unless you tell them.
  • Some email providers and phone services bundle fax-from-email as a built-in feature, so check your existing accounts before signing up elsewhere.

Setting up a free email-to-fax service

Start by choosing a service. eFax offers 10 free faxes per month through their online portal or by email. Fax.plus gives you 5 free faxes monthly. HelloFax (owned by HelloSign) allows 5 free faxes per month. Fax2Email and MyFax also have free tiers. Each service works slightly differently, so pick one and create an account on their website.

During signup, you will receive a unique fax number assigned to you, and you will be given the gateway email address format to use. For example, eFax might give you an address like yourname@efaxsend.com. Write down both your assigned fax number and the gateway address — you will need the gateway address to send faxes, and you may need your fax number if someone wants to send you a fax back.

Some services ask you to verify your email address by clicking a link in a confirmation email. Do this before you try to send your first fax, or the gateway may reject it.

Sending your first fax through email

Open your regular email account — Gmail, Outlook, Yahoo, or whatever you use daily. Create a new message and address it to the fax number in the format your service provided. If you are using eFax and sending to fax number 555-123-4567, the recipient address would be 5551234567@efaxsend.com. Check your service's instructions carefully, because the format varies slightly between providers.

In the subject line, write something brief like "Fax from [Your Name]" or leave it blank — most gateways ignore the subject line anyway. In the message body, you can write a short note if you want, but keep it straightforward. The gateway will fax whatever you write, so avoid long emails; stick to a sentence or two.

Attach your document. Most gateways accept PDF, Word (.doc or .docx), image files (JPG, PNG), and sometimes Excel or PowerPoint. If your document is a paper form you have scanned, save it as a PDF or JPG before attaching. Do not send files larger than 25 MB, as most gateways reject oversized attachments.

Hit send. The gateway usually processes the fax within a few minutes. Some services send you a confirmation email saying the fax was sent; others do not. If you do not hear back within 30 minutes, check your spam folder for a delivery notice, or log into your account on the service's website to see the status.

What happens if the fax fails

If the fax does not go through, the most common reason is a wrong fax number. Double-check the number with the recipient — fax numbers are straightforward to misread, especially over the phone. Make sure you have formatted it correctly for your gateway. Some gateways want dashes (555-123-4567), others want no dashes (5551234567), and some want a 1 in front for long distance.

The second most common issue is a busy or offline fax machine on the recipient's end. Fax machines that are powered off, out of paper, or in error mode will not receive faxes. Ask the recipient to check their machine and try again in a few minutes.

If your document failed to attach or the gateway rejected the file format, try converting it to PDF. Most services prefer PDF because it preserves formatting and is less likely to cause problems. You can convert Word documents to PDF in Word itself (File > Save As > PDF), or use a free online converter.

If you hit your monthly free fax limit, you will need to either wait until next month or upgrade to a paid plan. Some services let you buy additional faxes one at a time; others require a monthly subscription.

Built-in fax features in your existing accounts

Before you sign up for a separate service, check whether you already have fax-from-email built in. Google Voice users can send faxes through Gmail if they have a Voice number. Microsoft 365 subscribers (formerly Office 365) can use the Fax feature in Outlook if their organization has set it up. Some VoIP phone services like Vonage or Ooma include fax-from-email as part of their package.

If you have a home phone line through your internet provider, ask whether they offer fax services. Many do, and you may already be paying for it without realizing it. Check your account settings or call their support line.

Using a built-in feature is often simpler than signing up for a third-party service because you do not need to remember a separate gateway address or manage another account. The fax usually sends from your existing email address, so the recipient sees it as coming from you directly.

Receiving faxes through email

Most email-to-fax services also let you receive faxes, and they arrive as email attachments. When someone faxes your assigned fax number, the gateway converts the incoming fax to a PDF or image file and emails it to you. This is useful if you want a single inbox for both email and faxes.

Incoming faxes usually arrive within a few minutes of being sent. The email will come from the gateway service (like noreply@efax.com) with the sender's fax number in the subject line or message body. You can then read the attachment, print it, or forward it to someone else.

If you do not want to receive faxes, most services let you disable incoming fax delivery in your account settings. You can still send faxes; you just will not receive them.

Frequently Asked Questions

Can I send a fax to an international fax number?

Yes, most gateways support international faxes, but they usually charge more per page than domestic faxes. Check your service's pricing for the country you are sending to. You will need to include the country code in the fax number — for example, 44 for the United Kingdom or 33 for France.

What if I need to send a fax with multiple pages?

Attach all pages as a single PDF file, or attach multiple files. The gateway will send them as one fax transmission. If you are attaching separate image files (like scanned pages), number them in the filename so the gateway sends them in the right order.

Can the recipient tell the fax came from email?

No. The fax arrives on their machine looking like a standard fax. There is no indication it came from email unless you mention it in the message or they recognize your email address in the cover page.

What if my free fax limit runs out mid-month?

You will need to wait until your account resets next month, or upgrade to a paid plan. Some services let you buy a small pack of additional faxes (like 5 or 10) without committing to a full monthly subscription.

Is email-to-fax find for sensitive documents?

Email-to-fax is as find as regular email and fax combined — which means it is not encrypted by default. If you are sending highly sensitive information like medical records or financial documents, ask your service whether they offer encryption, or use a paid service with stronger security features.