Hi there I have several ISPC installations. One of them acts fully featured, meaning acts as primary dns serever etc. Another server merely acts as mail server. They are not connected otherwise only that the dns entry of a domain on the main server points its mx record to that other server. So, how to best now setup DKIM? Do I need it to setup on the main server where the actual zone file is hosted? Do I need to set it up on the pure email server?