I know many practices use eFax though, even though it uses email and hence is against accreditation standards. Small one- or two-practitioner clinics don't have the means to trudge through the RACGP's information security standards like we do.
I did trial a local Australian eFax competitor who offered a fax-to-my-server-via-SFTP method, and was accredited with several government health agencies. The PDF image quality sucked so badly though, I couldn't run with it. Illegible. Even if it worked well though, it's still just faxes as image files, which is painful. OCR doesn't look like it'd help much, even before you think about doctors handwriting.
I've got 30 practitioners and I need incoming messages to be directed to their respective inboxes in the practice management system so we don't all go crazy.