>I want to determine the standard email client. How can I do this.
>The reason to find out which client is used is, that I want to use Outlook automation if it is Outlook, in the other case I want to use ShellExecute.

You could try to create an Outlook object, then if that fails, go on to use ShellExecute

LOCAL loMail
loMail = CREATEOBJECT("Outlook.Application") && Not sure if classname is correct
IF VARTYPE( loMail) = "O" AND NOT ISNULL( loMail)
Do Outlook stuff
ELSE
Do ShellExecute Stuff
ENDIF