Create a new mail where the recipient is the FAX number followed by the domain, attach a PDF file in A4 format, and paste your Fax key provided by Mixvoip in the subject or in the message body.

Recipient: (number must be numeric and can look like 004969… for international calls or 20333390 for national ones for example)


The PDF file must be in A4 format 210 x 297 mm (21 x 29,7 cm)

Features and limitations

FAX key is only usable from the same domain as the email address shown on the page you retrieved the FAX key from

  • Supports 1-5 documents per e-mail
  • Supports up to 5 different recipients
  • Supports PDF
  • Documents should be in portrait, not landscape format

FAX key

Your FAX key can be retrieved from our web interface in the user settings section. This page is accessible by going to the ‘User management’ menu and clicking on the username you want to send a fax from.

Technical details

The fax key is a 9 characters long sub-string of the concatenated md5 hash of the username, password, and the suffix string “faxkey”, prefixed by the user’s account code.