How to send a fax through email with Dropbox Fax

Updated Dec 04, 2025

Sending a fax

Note: Email aliases aren’t supported in the email-to-fax feature. Make sure you send your faxes from an email address that matches your HelloFax account email, and doesn’t have any aliases configured to it.

To send a fax from your email:

Open a new email.
In the “To” field, add the recipient’s fax number with no spaces or special characters, followed by “@hellofax.com”.
- To send the fax to a US number, add 1 to the beginning of the fax number. For example, “19992345678@hellofax.com”.
- To send the fax to a non-US number, add 00 and the destination country code to the beginning of the fax number. For example, “00429875555@hellofax.com”.
Add a subject line. This appears in the “To” field on the fax cover page.
Add body text to your email. This becomes the message on the cover page, but it’s not required.
Attach the document you want to fax.
Click Send.

Note: If you have an image or any other graphic in your email signature, your fax may not be delivered due to process failures. To prevent this issue, you can do one of the following:

Remove the graphics from your signature manually.
Check with your email provider to create a rule that dynamically removes your signature for the hellofax.com recipient.

Email authentication

Email authentication is especially crucial when utilizing the email-to-fax feature, as it ensures that the emails we receive are genuinely sent by you. This security measure mitigates the risk of abuse by preventing unauthorized individuals from impersonating your email account.

To set up email authentication:

Log in to hellofax.com.
Hover over your initials in the top-right corner.
Click My Settings > Profile.
Scroll down to Email Authentication.
- Check the box next to Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM), or both.
Click Save at the bottom of the page.

Note: Activating email authentication settings helps ensure the delivery of your email to other recipients. Many email providers block unauthenticated emails due to the heightened risk of being spam. Contact your email provider for further advice on configuring your email authentication settings.

Testing your email authentication

You can send a fax through email to test your email authentication setup. To verify proper configuration, use a mail testing tool such as https://www.mail-tester.com/. Simply send a fax that is addressed to the email generated by the mail testing service. After a brief period, the service will display a report indicating if anything is misconfigured.

If everything is in order, the report should indicate that SPF and DKIM are correctly configured. Here’s an example: