Firstly, stop "EmailArchitect Super Service" from "Control Panel -> Administrative
Tools -> Services"; and start EmailArchitect Server process like this:
Start menu -> Run, input "c:\program files\emailarchitect\emailarchitectsvr" /s
and press enter
Open Windows Task Manager and switch to Processes list, highlight "EmailArchitectSvr" process and right click mouse to choose "Debug". Your Visual C++ IDE will be prompted to debug it. After the IDE started, choose menu "Project" -> "Setting" -> "Debug" select "Additional DLL" and input the full path of your filter dll.
Finally, open your filter source file in this IDE, and set a break point. After you finished the debug, you need to restart "EmailArchitect Super Service" in "Administrative Tools" -> "Services".