Faxing is still common and is frequently used to send personal data, especially in the real estate and medical industry. It needs to be secure.
The sending of a fax in the old days was actually quite secure. It went from one machine directly to another one. No middleman handled the processing. Here’s an article on sending documents securely. Its’ still relevant today.
However, today’s technology usually involved the fax ending up in someone’s e-mail and probably downloaded to their computer. So, that part can be insecure. Another issue is the fax processor. They receive the fax, convert it digitally, and send it to you. So now, there’s a copy of the fax on their servers. You have no control over their security.
So, the two main issues are the security of your e-mail AND the security of the fax provider. The third, and most concerning issue, is that some ‘free fax’ providers will scan your messages for marketing purposes. This is similar to how the free e-mail providers scan your e-mail and then suddenly they are marketing things to you that seem suspiciously relevant. Thus, an online fax service can have several vulnerabilities that never existed on the old fax to fax services over plain old telephone lines.
Another issue is with file formats. Generally, e-mail faxes can only send and receive PDFs and Office documents like Word and Excel. Images never faxed well on the old machines and image formats like JPG and GIF are just not compatible with the current faxing technology.
Then, there’s the individual service providers. Some require annual contracts. Others have strict limits on usage and can (often) send surprise billings for ‘over usage fees’.
Storage is another concern. If they are storing your faxes and they can be retrieved by anyone with your password then they are not truly secure there.
At Faxtopia, all faxes are deleted from their servers upon successful delivery. That actually serves two good purposes. It eliminates any hacking, and it keeps down the costs of running cloud servers.
Overall, online fax security should mostly be concerned about your e-mail systems.