ok el problema es outlook express.
Prueba esto
Código:
procedure TForm1.Button1Click(Sender: TObject);
const
olMailItem = 0;
var
Outlook, MailItem: OLEVariant;
begin
try
Outlook := GetActiveOleObject('Outlook.Application');
except
Outlook := CreateOleObject('Outlook.Application');
end;
MailItem := Outlook.CreateItem(olMailItem);
MailItem.Recipients.Add('delphi at elists.org');
MailItem.Subject := 'your subject';
MailItem.Body := 'Visit: http://www.elists.org/mailman/listinfo/delphi';
MailItem.Attachments.Add('C:\autoexec.bat');
MailItem.Send;
Outlook := Unassigned;
end;
Uses
Comobj
Suerte, a vder si sirve de algo.
Saludos