Open folder explorer under your exMon Administrator path.

The path can be found by right clicking on exMon Administrator in task bar and right clicking again on exMon Administrator in the popup, then select Properties like this:

When you have your path, enter it in folder explorer:

Then type cmd in the path and press enter:

Now you have command line open and you can type the following to test your smtp configuration:

epcmd --testemail {}