Instead of launching SendEmail.exe directly in the task, launch Start
with SendEmail as an argument. That way you can then take advantage of Start's ability to run minimized.
From Start /?
:
MIN Start window minimized.
So change the "Program/Script" to start
and then add "" /Min "c:\sendEmail-v156\sendemail.exe" <your arguments for SendEmail>
in the "Add arguments (optional)" field.