How do I set the fields CustomerID not linking to
index.pl?Action=AgentCustomerInformationCenter;CustomerID=something% 40gmail.com
I want to linking to, for example: https://www.google.rs/search?q=something@gmail.com
You should copy & paste from /opt/otrs/Kernel/Config/Defaults.pm the section related to customer configuration into /opt/otrs/Kernel/Config.pm (or better define a pretty new file as a copy of /opt/otrs/Kernel/Config.pm and put it into /opt/otrs/Custom/Kernel/Config.pm).
And then edit your Config.pm
Mind: never edit the Defaults.pm directly.
OTRS 6.0.x on CentOS 7.x with MariaDB 10.2.x database connected to an Active Directory for Agents and Customers.
ITSM and FAQ modules installed.