- How email-to-fax works behind the scenes
- The email address format, provider by provider
- Sending your first email fax, step by step
- Attachments and file types email fax accepts
- Using the email body as a cover sheet
- Delivery confirmations and fax-to-email inboxes
- Keeping email faxes secure
- Fixing email faxes that fail
- Frequently asked questions
To send a fax from email, sign up with an email-to-fax service, then write a new email from your registered address to the fax number followed by the provider's domain, such as [email protected]. Attach the document, use the body as a cover note and press send. You'll get a confirmation email.
If you've been asked to fax something and the nearest fax machine is a distant memory, your inbox can do the job. Email-to-fax services take an ordinary email, turn the attachment into a fax and deliver it to a real fax machine at the other end. You type an address, attach a file and press send, the same as any email. I've put this guide together from the help centres of three providers that document it clearly, FAX.PLUS, iFax and eFax, so the steps match what they say rather than guesswork.
How email-to-fax works behind the scenes
Your email goes to the fax provider, not straight to the recipient. The provider reads the destination number from the address, converts your attachment into fax pages and dials the recipient's fax line. The person at the other end gets a normal fax. You then get an email back telling you whether it went through.
Because the provider does the dialling, you need an account with one of these services first. Each one checks that the email comes from an address registered to your account, which stops strangers sending faxes in your name.
The email address format, provider by provider
Every service uses the same idea: the recipient's fax number, an @ sign, then the provider's domain. The details differ, so follow your own provider's help page.
| Service | What goes in the To field | Note from its help page |
|---|---|---|
| FAX.PLUS | +[country code][area code][number]@fax.plus | Separate several recipients with commas |
| iFax | [fax number]@ifaxapp.com | Send from an email registered to your iFax account |
| eFax | [fax number]@efaxsend.com | Use the full number including country code |
Leave out spaces, dashes and brackets in the number. For international faxes, include the country code; eFax's help centre says to use the complete number with country code, city code and local number.
Sending your first email fax, step by step
- Open your email app or webmail, whichever you use for work.
- Start a new message from the email address registered with your fax service.
- In the To field, type the fax number followed by your provider's domain, in the format shown above.
- Add a subject line if your provider uses it (iFax puts it on the cover page; FAX.PLUS shows it as a note in your sent faxes).
- Type any cover message in the body of the email.
- Attach the document you want to fax.
- Press Send, then watch for the confirmation email.
FAX.PLUS also asks you to switch on a setting first: in its web app, under Settings, then the Faxing tab and Email to Fax, you turn on the option to send faxes by email. Its help centre says email-to-fax isn't part of its free plan, so check what your account includes before you rely on it.
Attachments and file types email fax accepts
Stick to common document formats and you'll rarely have trouble. FAX.PLUS lists PDF, DOC, DOCX, XLS, XLSX, PNG, JPG, RTF and TIFF. iFax's email guide mentions PDF and Word documents. eFax's help centre says you can attach up to ten files to one email fax.
- Save documents as PDF where you can; layouts hold together better.
- Check the pages are the right way up before you send.
- Avoid very pale text or coloured backgrounds, which fax machines print poorly.
- If you've got paper pages, scan them first and attach the PDF.
- Combine several files into one PDF if the order matters.
If you need to fill in a form, sign it or merge pages before sending, my comparison of PDF editors covers tools that make that quick.
Using the email body as a cover sheet
A cover sheet tells the receiving office who the fax is for, who it's from and how many pages to expect. With email-to-fax you usually write it in the body of the email:
- FAX.PLUS: with Include Email Content in Fax switched on, the body becomes the first page. Switch it off and only the attachments are faxed.
- iFax: the subject appears as the cover page subject and the body appears as the cover page comment.
- eFax: its help centre says the body of the email works as your cover page.
Keep the cover short: recipient name and department, your name and a reply email, the number of pages and a line on what it's about. Leave your email signature off if it's long, or it'll end up printed on the fax.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
Delivery confirmations and fax-to-email inboxes
You'll get an email back once the provider has tried to deliver. FAX.PLUS says you get a delivery status email showing whether the fax went through, and it notifies you by email if a fax fails, with the reason. Keep these messages; they're your record that the document arrived.
It works the other way round too. With a fax number from your provider, incoming faxes can land in your inbox. FAX.PLUS's help centre explains how to have each received fax attached to an email as a PDF or TIFF, and how to forward them to up to five email addresses. eFax says you'll get an email notification for each fax sent to your eFax number. If your inbox is already busy, a separate address for faxes keeps them easy to find, and my guide to free email addresses for business walks through the options.
Keeping email faxes secure
- Send only from the email address registered with your fax account, and protect that inbox with two-step sign-in.
- Type the fax number carefully; a fax can't be pulled back once it's sent.
- Read your provider's security and compliance pages if you handle medical, legal or financial documents.
- Delete attachments from your sent folder if you don't need a copy kept there.
- Ask the recipient to confirm they've got it when the document's sensitive.
Fixing email faxes that fail
- Fax rejected straight away: you've probably sent from an address that isn't registered with the service. iFax says unregistered addresses fail.
- SPF error: eFax's help centre says SPF must be enabled on your email domain and can't be set to Neutral, or faxes sent by email will fail. Your email or domain host can check this.
- Wrong number format: remove spaces and add the country code.
- Feature not working at all: check the email-to-fax setting is on and that your account includes it.
- Unreadable pages: convert the file to PDF and resend.
If an AI writing assistant drafts your emails, keep it away from the To field on faxes. My roundup of AI email assistants covers tools that help with the writing while you stay in charge of where it goes.
Do you make an email-to-fax service? Tool makers can ask to be considered for a featured place on this list.
Frequently asked questions
Can I send a fax from Gmail or Outlook?
Yes. Any email app works once you have an account with an email-to-fax service. Address the email to the fax number at your provider's domain and attach the document.
Do I need a fax machine to send a fax by email?
No. The fax service converts your attachment and delivers it to the recipient's fax machine, so you only need email and an account with the service.
What do I put in the subject line?
It depends on the provider. Some use the subject on the cover page, others show it as a note in your sent faxes. Check your provider's help page.
Can I fax several people at once from email?
Some providers allow it. FAX.PLUS says you can add several fax addresses in the To field, separated by commas.
Can I receive faxes in my email?
Yes, if you have a fax number from an email-to-fax provider. Incoming faxes arrive as email attachments or notifications.
