Yeah, that's right, somebody sent me a fax, possibly from the the '90s, but I won't know until I am able to open it.
eFax Messenger won't install on my 64-bit Windows version, and the site won't let me download in anything other than .EFX format. I've since changed the setting to use PDF in the accounts panel, but it won't let me download old faxes in PDF.
Other than installing eFax into a 32-bit Windows VM, what other solutions are there that work on 64-bit Windows?
Update: Looks like downloading eFax 4.3 from CNET did the trick. Thanks!