When using the XMLAPI feature of FaxMaker you want to be sure the correct versions of MSXML are installed on your server for proper operation and not have any security risks as well. This article provides information about which versions are required for use with FaxMaker.
Currently, version 20 is the only supported version of FaxMaker this includes all builds of version 20, 20.4 for example. Version 20 uses both MSXML 6.0 and MSXML 3.0.
FaxMaker uses MSXML 6.0 in versions 18.3 and higher as MSXML 4.0 was retired by Microsoft.