[Exim] exim + perl question

i create my own script which return "yes" or "fail".
without exim it work ok.

exim always got return "yes" from script. what mean script work ok.

how wright condition for check returning values?

following does not work:
condition =${if eq {${perl{mysub}}} {(?i)Yes}
{1}{0}}
also in second part: or {"yes"} or {return "yes"}.


i'm confused.