Update your manual to include all available fields for Coverpage
I have discovered that several fields for coverpages exists that is not documented in your manual. https://manuals.gfi.com/en/FaxMakerOnline/content/topics/fmousers/creating_a_coverpage.htm
For example ~SenderEmail~ and ~SimpleFaxNumber~
The manual is not really useful if all availble fields are not documented. Even your customer support does not know that these fields exist.