GFI FaxMaker sometimes sends a large amount of extra blank pages, when using a custom coverpage.
A missing or incomplete HTML tag in the coverpage HTML file.
If you want to use a custom coverpage, you should rather start with a new coverpage, using the default coverpage as a sample.
Note: Make sure to use a plain text editor like Notepad. Do not use Wordpad or Word, as these editors can add brackets and parentheses and break the HTML code.
The default coverpage fixes the extra blank page issue.