tkt_sei_email_subject

You can use the filter tkt_sei_email_subject in order to customize the “About” of the Email sent with the TukuToi Send Email If Plugin.

You just need to return a valid Email “About” (string) in the callback function like in the below example.

add_filter('tkt_sei_email_subject', 'my_custom_email_subject');
function my_custom_email_subject(){
  $subject ='My Custom About'; 
  return $subject;
}