Why wait? This option has been available in the HylaFAX RPM since 4.1.7-1:
* Sun Jun 15 2003 Darren Nickerson <darren.nickerson@xxxxxxxx> 4.1.7-1
- update to official 4.1.7 release
- add metamail dependency
- [Bug 420] Add SaveUnconfirmedPages config option
(Lee Howard)
- [Bug 427] Fix problem with port/install.sh on non-root builds
(Giulio Orsero)
- [Bug 424] Add support for tracking CIDName and CIDNumber in
xferfaxlog, tiff files, and client/server protocol via hfaxd
(iFAX Solutions)
It defaults to true.
I don't use the RPM, so I've never noticed this before. The 4.1.8
release doesn't mention this feature on the website, is it included in
the 4.1.8 tar file?