Thank you for your reply.
We have several users on our limesurvey website. Everyone of them has its own unique email address. Everyone of them is also allowed to add new administrators. Now, lets say, user A has this email address: userA@domain.com. Under global settings we have this email address: superadmin@domain.com
Now, user A wants to add a new administrator. Creating the user works fine, however, the email including the password which is supposed to be sent by limesurvey to the new user is not sent because the email address of user A is userA@domain.com which does not match with the email of the superadmin.
So, if the plugin of DenisChenu was also applied to these global settings then userA could create new users and then when limesurvey would sent the password to the new user it would use the email settings of userA instead of the global email settings which do not work for user A.
If there is any other way to fix this issue I'm more than happy for any hints