RSRFCCHK is a tool for RFC destination test and you can also list out all the RFC destinations from here. So, no need to check, scroll one by one via transaction code SM59. You can also use transaction code RSRFCCHK to access the same screen.
Execute report RSRFCCHK via transaction code SE38. Here, you can select to display all the RFC destination list only or execute the connection test together. The connection test will take some time depend on how many RFC destinations that been maintained in your system. You can also specific on which connection type to display.
The result,
