All-
These are the installation steps I followed using CrossOver Linux Standard version 10.
-Download eFax Messenger for Windows from efax.com website.
-In Ubuntu click Crossover>Run a windows command>Use Bottle Microsoft Office 2007 (was defaulted for me)>Browse to the executable file msgrplus.exe>open>run>eFax Messenger Setup>OK>Next>Typical>I accept the Terms in the License Agreement>Install>Finish
-eFax will now automatically open. I didn't sign into eFax with an account, but I did open an eFax file with no errors.
Thanks,
kaizenlpi