Distinct() is used to remove all duplicate items from a list or a collection. To use this method on a property of a class, below is an extension method which you could use :

public static class MoreLinq 
{
    public static IEnumerable<T> DistinctByProperty<T, TKey>(this IEnumerable<T> items, Func<T, TKey> property)
    {
        return items.GroupBy(property).Select(x => x.First());
    }

    // more such extensions can go in here...
}

Above I have created an extension method called “DistinctByProperty”, now you can use this property like as shown below…

var distinctEmails = customers.DistinctByProperty(x => x.EmailAddress);

References