This feature is not supported yet for oVirt/RHV, XenServer, Solaris, OracleVM, Nutanix and MS Windows server/Hyper-V. It will come in future releases.
You are using LPAR2RRD Free Edition, only 3 top items are allowed. Consider to upgrade to the Enterprise Edition.
SMTP options (the same are used in Reporter)
Note: When empty then OS system defaults are used.