LINQ query to find if items in a list are contained in another list

For those who came after reading heading of the question :

bool doesL1ContainsL2 = l1.Intersect(l2).Count() == l2.Count;

L1 and L2 are both List<T>

A simple explanation is : If resulting Intersection of two iterables has the same length as that of the smaller list (L2 here) ,then all the elements must be there in bigger list (L1 here)

---

For those who read the whole question

var list3 =  test2.Where(x => !test1.Any(y => x.Contains(y)));

var output = emails.Where(e => domains.All(d => !e.EndsWith(d)));

Or if you prefer:

var output = emails.Where(e => !domains.Any(d => e.EndsWith(d)));

var test2NotInTest1 = test2.Where(t2 => test1.Count(t1 => t2.Contains(t1))==0);

Faster version as per Tim's suggestion:

var test2NotInTest1 = test2.Where(t2 => !test1.Any(t1 => t2.Contains(t1)));