How to open or convert old .efx (eFax) documents without PowerPC support?
Since you updated your settings to receive faxes now in PDF, you can: 


Fax the EFX documents to your assigned eFax® number (via website or
e-mail). 
The new files should be received as PDF.


If you need further assistance, please let us know and we can convert them to PDF for you.  You can respond to this thread or contact us on Twitter @efaxcares so we can exchange contact info.