This is updated for 2.5.47+. See the API page: GrouperShell (gsh) Email smtp (GrouperEmail)
Several features of Grouper use mail. You need to have an SMTP service to connect Grouper to. There is an external system for SMTP on the external systems screen
You cannot add a new SMTP external system since only one can exist and it already exists.
You cannot delete the SMTP external system since it can only be disabled.
Edit the SMTP settings