You are not able to add an email address to the Auto Remediation Settings page in ClientNet while using Internet Explorer 11.
Nothing happens when you click on the Add Icon "+" to add a new Administrator Email.
ClientNet
This is occuring due to an unsupported javascript method on an older 'minor version' of Internet Explorer 11 ( IE Version 11.0.10240.16384 )
To check the exact version you are on click on Help > About IE
Upgrade to to the latest version of Internet Explorer 11