-DEBUG or -D command displays febootimail internal variables. This allows to compare actual configuration with all command line parameters.
Also, SMTP server responses are shown, allowing to check if there are no problems with remote machine.
C:\>febootimail -SERVER smtp.server.com -FROM email@example.com -TO firstname.lastname@example.org -TEXT Simple email debugging -DEBUG
Note that it is possible to log debug information by adding redirection operator >> (two consecutive greater than signs) that will write febootimail screen output to file (or append to existing one).
If you have any questions, please do not hesitate to contact our support team.