OleDbConnection

DateTime bugun = DateTime.Now;

string constr = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Documents and Settings\Arastokrat.DYGOR-MOBILE\Belgelerim\Visual Studio 2008\Projects\WebSite1\DB\GelecegeMektupDB.accdb";
OleDbConnection con = new OleDbConnection(constr);

string query = "SELECT * FROM Mektuplar WHERE Tarih=@tarih;";
OleDbCommand cmd = new OleDbCommand(query, con);

cmd.Parameters.Add("@tarih", OleDbType.DBDate).Value = bugun;

OleDbDataAdapter dap = new OleDbDataAdapter(cmd);
DataSet ds = new DataSet();
dap.Fill(ds);

try
{
con.Open();

OleDbDataReader dr = cmd.ExecuteReader();

while (dr.Read())
{
if (dr.GetString(4).Equals(DateTime.Now.ToShortDateString()))
{
emailGonder(dr.GetString(1),dr.GetString(2),dr.GetString(3),dr.GetString(5));
}
}

dr.Close();
Response.Write("");
}
catch (Exception hata)
{
}
finally
{
con.Close();
}