Sites.cs

[XmlRoot(ElementName = "sites")]
public class Sites
{
    [XmlElement(ElementName = "site")]
    public List<Site> Site { get; set; }
}

[XmlRoot(ElementName = "site")]
public class Site
{
    [XmlElement(ElementName = "redirects")]
    public Redirects Redirects { get; set; }

    [XmlAttribute(AttributeName = "url")]
    public string Url { get; set; }

    [XmlAttribute(AttributeName = "name")]
    public string Name { get; set; }
}

[XmlRoot(ElementName = "redirects")]
public class Redirects
{
    [XmlElement(ElementName = "redirect")]
    public List<Redirect> Redirect { get; set; }
}

[XmlRoot(ElementName = "redirect")]
public class Redirect
{
    [XmlAttribute(AttributeName = "from")]
    public string From { get; set; }

    [XmlAttribute(AttributeName = "to")]
    public string To { get; set; }
}