SPList.IsThrottled property

Gets a value that indicates whether the total number of items exceeds the upper limit set for the list.

Namespace:  Microsoft.SharePoint
Assembly:  Microsoft.SharePoint (in Microsoft.SharePoint.dll)

public bool IsThrottled { get; }

Property value

Type: System.Boolean
true if the value of the ItemCount property is greater than the value of the MaxItemsPerThrottledOperation property for the Web application; otherwise, false.