Here is a simple test program.
This example is using directly the TIdSMTP class of Indy, but using the corresponding visual component of Indy instead is of course also possible: see "Indy Clients Protocols (nz)" panel in the IDE component palette.
Fields that must absolutely be changed in this sample (in "TForm1.Button2Click" code):
-IdMessage.Recipients.EmailAddresses : must have a valid recipient email address
-IdSMTP.Host: probably your own SMTP server (i.e. SMTP server of your ISP)
-IdSMTP.Port: eventually, the port number of the targeted SMTP server (25 in this sample)
Change the other fields according to your own needs.
** EDIT (2014-06-09) ** : Updated version for this sample. Indy dependency has been added to the test project for portable consideration (direct path to Indy library no more needed).