Private Sub DataGridView1_CellContentClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
If Directcast(DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex),CheckBoxColumn).Checked = True Then
MessageBox.Show("Email inesistente", "Receive.net", MessageBoxButtons.OK, MessageBoxIcon.Warning)
Return
End If
End Sub