alternative is YAC Number Basic http://www.yac.com.
As efax but the fax is sent to your email address as either a PDF or TIFF document. This means there is no software to download.
From their home page choose "YAC Number", then "Try our YAC Number BASIC service for free" icon.
Depending on how you set it up, this service also offers voicemail to email.
I've used the free fax to email service for over two years with no problems.