在窗体的构造函数中添加以下代码：
__fastcall TMainForm::TMainForm(TComponent* Owner)
        : TForm(Owner)
{
    unsigned mask = SendMessage(RichEdit1->Handle, EM_GETEVENTMASK, 0, 0);
    SendMessage(RichEdit1->Handle, EM_SETEVENTMASK, 0, mask | ENM_LINK);
    SendMessage(RichEdit1->Handle, EM_AUTOURLDETECT, true, 0);  //自动检测URL

    RichEdit1->Text = "欢迎访问C++ Builder\n"
                      "网址: http://www.ccrun.com\n"
                      "偶的信箱:\n"
                      "mailto::[email protected] \n"
                      "嘿嘿\n";
}

重载窗体的WndProc

1。在.h中添加：

   protected:
      virtual void __fastcall WndProc(Messages::TMessage &Message);

2。在.cpp中添加：
//---------------------------------------------------------------------------
void __fastcall TMainForm::WndProc(Messages::TMessage &Message)
{
    if (Message.Msg == WM_NOTIFY)
    {
        if (((LPNMHDR)Message.LParam)->code == EN_LINK)
        {
            ENLINK* p = (ENLINK *)Message.LParam;
            if (p->msg == WM_LBUTTONDOWN)
            {
                SendMessage(RichEdit1->Handle, EM_EXSETSEL, 0, (LPARAM)&(p->chrg));
                ShellExecute(Handle, "open", RichEdit1->SelText.c_str(), 0, 0, SW_SHOWNORMAL);
            }
        }
    }
    TForm::WndProc(Message);
}


以上代码均已测试通过。