Maybe try removing
[vbld_EscapeString(vbld_FSO.OpenTextFile("%CURRENT_ UT_EMAIL_OUTPUT_FOLDER%\index.html", , , True).ReadAll)]
from the Send Mail step and instead attach the file %CURRENT_UT_EMAIL_OUTPUT_FOLDER%\index.html (to eliminate the script expression).
You might also try recreating the build machine from scratch.
Otherwise we would need more details to try to reproduce the problem here.
http://www.kinook.com/Forum/showthre...?threadid=3044