diff --git a/.travis.yml b/.travis.yml
index 8fd7aae3d..851a3773d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,4 +10,7 @@ rvm:
 - jruby-19mode
 
 before_install:
+- gem install bundler -v 1.12
+- gem update --system
+- bundle --version
 - gem --version
diff --git a/lib/bugsnag.rb b/lib/bugsnag.rb
index 8c6c8b046..e14ea2407 100644
--- a/lib/bugsnag.rb
+++ b/lib/bugsnag.rb
@@ -24,6 +24,7 @@
 require "bugsnag/middleware/mailman"
 require "bugsnag/middleware/rake"
 require "bugsnag/middleware/callbacks"
+require "bugsnag/middleware/classify_error"
 
 module Bugsnag
   LOG_PREFIX = "** [Bugsnag] "
@@ -43,6 +44,9 @@ def configure(config_hash=nil)
       # Use resque for asynchronous notification if required
       require "bugsnag/delay/resque" if configuration.delay_with_resque && defined?(Resque)
 
+      # Add info error classifier to internal middleware
+      configuration.internal_middleware.use(Bugsnag::Middleware::ClassifyError)
+
       # Warn if an api_key hasn't been set
       @key_warning = false unless defined?(@key_warning)
 
@@ -64,8 +68,19 @@ def configure(config_hash=nil)
     def notify(exception, overrides=nil, request_data=nil, &block)
       notification = Notification.new(exception, configuration, overrides, request_data)
 
+      initial_severity = notification.severity
+      initial_reason = notification.severity_reason
+
       yield(notification) if block_given?
 
+      if notification.severity != initial_severity
+        notification.severity_reason = {
+          :type => Bugsnag::Notification::USER_CALLBACK_SET_SEVERITY
+        }
+      else
+        notification.severity_reason = initial_reason
+      end
+
       unless notification.ignore?
         notification.deliver
         notification
@@ -80,7 +95,8 @@ def notify(exception, overrides=nil, request_data=nil, &block)
     # error class
     def auto_notify(exception, overrides=nil, request_data=nil, &block)
       overrides ||= {}
-      overrides.merge!({:severity => "error"})
+      overrides[:severity] = "error" unless overrides.has_key? :severity
+      overrides[:unhandled] = true unless overrides.has_key? :unhandled
       notify_or_ignore(exception, overrides, request_data, &block) if configuration.auto_notify
     end
 
diff --git a/lib/bugsnag/configuration.rb b/lib/bugsnag/configuration.rb
index f5a2ac159..c5c9bb9e4 100644
--- a/lib/bugsnag/configuration.rb
+++ b/lib/bugsnag/configuration.rb
@@ -45,20 +45,6 @@ class Configuration
       "rack.request.form_vars"
     ].freeze
 
-    DEFAULT_IGNORE_CLASSES = [
-      "AbstractController::ActionNotFound",
-      "ActionController::InvalidAuthenticityToken",
-      "ActionController::ParameterMissing",
-      "ActionController::UnknownAction",
-      "ActionController::UnknownFormat",
-      "ActionController::UnknownHttpMethod",
-      "ActiveRecord::RecordNotFound",
-      "CGI::Session::CookieStore::TamperedWithCookie",
-      "Mongoid::Errors::DocumentNotFound",
-      "SignalException",
-      "SystemExit",
-    ].freeze
-
     DEFAULT_IGNORE_USER_AGENTS = [].freeze
 
     DEFAULT_DELIVERY_METHOD = :thread_queue
@@ -72,7 +58,7 @@ def initialize
       self.send_environment = false
       self.send_code = true
       self.params_filters = Set.new(DEFAULT_PARAMS_FILTERS)
-      self.ignore_classes = Set.new(DEFAULT_IGNORE_CLASSES)
+      self.ignore_classes = Set.new()
       self.ignore_user_agents = Set.new(DEFAULT_IGNORE_USER_AGENTS)
       self.endpoint = DEFAULT_ENDPOINT
       self.hostname = default_hostname
diff --git a/lib/bugsnag/delayed_job.rb b/lib/bugsnag/delayed_job.rb
index 2f842acc1..abd04d3c7 100644
--- a/lib/bugsnag/delayed_job.rb
+++ b/lib/bugsnag/delayed_job.rb
@@ -17,6 +17,12 @@ def error(job, error)
               :job => {
                 :class => job.class.name,
                 :id => job.id,
+              },
+              :severity_reason => {
+                :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+                :attributes => {
+                  :framework => "DelayedJob"
+                }
               }
             }
             if job.respond_to?(:queue) && (queue = job.queue)
diff --git a/lib/bugsnag/mailman.rb b/lib/bugsnag/mailman.rb
index 142f59267..92515b8f5 100644
--- a/lib/bugsnag/mailman.rb
+++ b/lib/bugsnag/mailman.rb
@@ -15,7 +15,14 @@ def call(mail)
         yield
       rescue Exception => ex
         raise ex if [Interrupt, SystemExit, SignalException].include? ex.class
-        Bugsnag.auto_notify(ex)
+        Bugsnag.auto_notify(ex, {
+          :severity_reason => {
+            :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+            :attributes => {
+              :framework => "Mailman"
+            }
+          }
+        })
         raise
       ensure
         Bugsnag.clear_request_data
diff --git a/lib/bugsnag/middleware/classify_error.rb b/lib/bugsnag/middleware/classify_error.rb
new file mode 100644
index 000000000..e6a553110
--- /dev/null
+++ b/lib/bugsnag/middleware/classify_error.rb
@@ -0,0 +1,53 @@
+module Bugsnag::Middleware
+  class ClassifyError
+    INFO_CLASSES = [
+        "AbstractController::ActionNotFound",
+        "ActionController::InvalidAuthenticityToken",
+        "ActionController::ParameterMissing",
+        "ActionController::UnknownAction",
+        "ActionController::UnknownFormat",
+        "ActionController::UnknownHttpMethod",
+        "ActiveRecord::RecordNotFound",
+        "CGI::Session::CookieStore::TamperedWithCookie",
+        "Mongoid::Errors::DocumentNotFound",
+        "SignalException",
+        "SystemExit"
+    ]
+
+    def initialize(bugsnag)
+      @bugsnag = bugsnag
+    end
+
+    def call(notification)
+      notification.exceptions.each do |ex|
+
+        outer_break = false
+
+        ancestor_chain = ex.class.ancestors.select {
+          |ancestor| ancestor.is_a?(Class) 
+        }.map {
+          |ancestor| ancestor.to_s
+        }
+
+        INFO_CLASSES.each do |info_class|
+          if ancestor_chain.include?(info_class)
+            notification.severity_reason = {
+              :type => Bugsnag::Notification::ERROR_CLASS,
+              :attributes => {
+                :errorClass => info_class
+              }
+            }
+            notification.severity = 'info'
+            outer_break = true
+            break
+          end
+        end
+
+        break if outer_break
+      end
+
+      @bugsnag.call(notification)
+    end
+  end
+end
+    
\ No newline at end of file
diff --git a/lib/bugsnag/notification.rb b/lib/bugsnag/notification.rb
index 76a44ed86..5290ab988 100644
--- a/lib/bugsnag/notification.rb
+++ b/lib/bugsnag/notification.rb
@@ -15,6 +15,13 @@ class Notification
     NOTIFIER_VERSION = Bugsnag::VERSION
     NOTIFIER_URL = "http://www.bugsnag.com"
 
+    HANDLED_EXCEPTION = "handledException"
+    UNHANDLED_EXCEPTION = "unhandledException"
+    UNHANDLED_EXCEPTION_MIDDLEWARE = "unhandledExceptionMiddleware"
+    ERROR_CLASS = "errorClass"
+    USER_SPECIFIED_SEVERITY = "userSpecifiedSeverity"
+    USER_CALLBACK_SET_SEVERITY = "userCallbackSetSeverity"
+
     API_KEY_REGEX = /[0-9a-f]{32}/i
 
     # e.g. "org/jruby/RubyKernel.java:1264:in `catch'"
@@ -31,6 +38,8 @@ class Notification
 
     attr_accessor :context
     attr_reader :user
+    attr_reader :severity
+    attr_accessor :severity_reason
     attr_accessor :configuration
     attr_accessor :meta_data
 
@@ -50,10 +59,36 @@ def initialize(exception, configuration, overrides = nil, request_data = nil)
       @user = {}
       @should_ignore = false
       @severity = nil
+      @unhandled = false
+      @severity_reason = nil
       @grouping_hash = nil
       @delivery_method = nil
 
-      self.severity = @overrides[:severity]
+      if @overrides.key? :unhandled
+        @unhandled = @overrides[:unhandled]
+        @overrides.delete :unhandled
+      end
+
+      valid_severity = @overrides.key?(:severity) && SUPPORTED_SEVERITIES.include?(@overrides[:severity])
+      has_reason = @overrides.key? :severity_reason
+
+      if valid_severity && has_reason
+        @severity = @overrides[:severity]
+        @severity_reason = @overrides[:severity_reason]
+      elsif valid_severity
+        @severity = @overrides[:severity]
+        @severity_reason = {
+          :type => USER_SPECIFIED_SEVERITY
+        }
+      elsif has_reason
+        @severity_reason = @overrides[:severity_reason]
+      else
+        @severity_reason = {
+          :type => HANDLED_EXCEPTION
+        }
+      end
+      
+      @overrides.delete :severity_reason
       @overrides.delete :severity
 
       if @overrides.key? :grouping_hash
@@ -214,12 +249,19 @@ def deliver
       # make meta_data available to public middleware
       @meta_data = generate_meta_data(@exceptions, @overrides)
 
+      initial_severity = self.severity
+
       # Run the middleware here (including Bugsnag::Middleware::Callbacks)
       # at the end of the middleware stack, execute the actual notification delivery
       @configuration.middleware.run(self) do
         # This supports self.ignore! for before_notify_callbacks.
         return if @should_ignore
 
+        # Check to see if the severity has been changed
+        if initial_severity != self.severity
+
+        end
+
         # Build the endpoint url
         endpoint = (@configuration.use_ssl ? "https://" : "http://") + @configuration.endpoint
         Bugsnag.log("Notifying #{endpoint} of #{@exceptions.last.class}")
@@ -243,6 +285,8 @@ def build_exception_payload
         :payloadVersion => payload_version,
         :exceptions => exception_list,
         :severity => self.severity,
+        :unhandled => @unhandled,
+        :severityReason => @severity_reason,
         :groupingHash => self.grouping_hash,
       }
 
diff --git a/lib/bugsnag/que.rb b/lib/bugsnag/que.rb
index 2eaae4f07..5cdba68f6 100644
--- a/lib/bugsnag/que.rb
+++ b/lib/bugsnag/que.rb
@@ -3,7 +3,14 @@
     begin
       job = job.dup # Make sure the original job object is not mutated.
 
-      Bugsnag.auto_notify(error) do |notification|
+      Bugsnag.auto_notify(error, {
+        :severity_reason => {
+          :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+          :attributes => {
+            :framework => "Que"
+          }
+        }
+      }) do |notification|
         job[:error_count] += 1
 
         # If the job was scheduled using ActiveJob then unwrap the job details for clarity:
diff --git a/lib/bugsnag/rack.rb b/lib/bugsnag/rack.rb
index 17c8f59b4..41bd15231 100644
--- a/lib/bugsnag/rack.rb
+++ b/lib/bugsnag/rack.rb
@@ -1,5 +1,13 @@
 module Bugsnag
   class Rack
+
+    SEVERITY_REASON = {
+      :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+      :attributes => {
+        :framework => "Rack"
+      }
+    }
+
     def initialize(app)
       @app = app
 
@@ -34,7 +42,9 @@ def call(env)
         response = @app.call(env)
       rescue Exception => raised
         # Notify bugsnag of rack exceptions
-        Bugsnag.auto_notify(raised)
+        Bugsnag.auto_notify(raised, {
+          :severity_reason => SEVERITY_REASON
+        })
 
         # Re-raise the exception
         raise
@@ -42,7 +52,9 @@ def call(env)
 
       # Notify bugsnag of rack exceptions
       if env["rack.exception"]
-        Bugsnag.auto_notify(env["rack.exception"])
+        Bugsnag.auto_notify(env["rack.exception"], {
+          :severity_reason => SEVERITY_REASON
+        })
       end
 
       response
diff --git a/lib/bugsnag/rails/action_controller_rescue.rb b/lib/bugsnag/rails/action_controller_rescue.rb
index 6125e9cd6..a0c0649fc 100644
--- a/lib/bugsnag/rails/action_controller_rescue.rb
+++ b/lib/bugsnag/rails/action_controller_rescue.rb
@@ -1,6 +1,14 @@
 # Rails 2.x only
 module Bugsnag::Rails
   module ActionControllerRescue
+
+    SEVERITY_REASON = {
+      :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+      :attributes => {
+        :framework => "Rails"
+      }
+    }
+
     def self.included(base)
       base.extend(ClassMethods)
 
@@ -22,13 +30,17 @@ def set_bugsnag_request_data
     end
 
     def rescue_action_in_public_with_bugsnag(exception)
-      Bugsnag.auto_notify(exception)
+      Bugsnag.auto_notify(exception, {
+        :severity_reason => SEVERITY_REASON
+      })
 
       rescue_action_in_public_without_bugsnag(exception)
     end
 
     def rescue_action_locally_with_bugsnag(exception)
-      Bugsnag.auto_notify(exception)
+      Bugsnag.auto_notify(exception, {
+        :severity_reason => SEVERITY_REASON
+      })
 
       rescue_action_locally_without_bugsnag(exception)
     end
diff --git a/lib/bugsnag/rails/active_record_rescue.rb b/lib/bugsnag/rails/active_record_rescue.rb
index dfc9e4745..24c6516e0 100644
--- a/lib/bugsnag/rails/active_record_rescue.rb
+++ b/lib/bugsnag/rails/active_record_rescue.rb
@@ -8,7 +8,14 @@ def run_callbacks(kind, *args, &block)
           super
         rescue StandardError => exception
           # This exception will NOT be escalated, so notify it here.
-          Bugsnag.auto_notify(exception)
+          Bugsnag.auto_notify(exception, {
+            :severity_reason => {
+              :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+              :attributes => {
+                :framework => "Rails"
+              }
+            }
+          })
           raise
         end
       else
diff --git a/lib/bugsnag/railtie.rb b/lib/bugsnag/railtie.rb
index 799373b31..481a433a1 100644
--- a/lib/bugsnag/railtie.rb
+++ b/lib/bugsnag/railtie.rb
@@ -17,7 +17,14 @@ class Railtie < Rails::Railtie
       runner do
         at_exit do
           if $!
-            Bugsnag.auto_notify($!)
+            Bugsnag.auto_notify($!, {
+              :severity_reason => {
+                :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+                :attributes => {
+                  :framework => "Rails"
+                }
+              }
+            })
           end
         end
       end
diff --git a/lib/bugsnag/rake.rb b/lib/bugsnag/rake.rb
index 9a2cb75e4..74261a977 100644
--- a/lib/bugsnag/rake.rb
+++ b/lib/bugsnag/rake.rb
@@ -12,7 +12,14 @@ def execute_with_bugsnag(args=nil)
     execute_without_bugsnag(args)
 
   rescue Exception => ex
-    Bugsnag.auto_notify(ex)
+    Bugsnag.auto_notify(ex, {
+      :severity_reason => {
+        :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+        :attributes => {
+          :framework => "Rake"
+        }
+      }
+    })
     raise
   ensure
     Bugsnag.set_request_data :bugsnag_running_task, old_task
diff --git a/lib/bugsnag/resque.rb b/lib/bugsnag/resque.rb
index 4f9b3b428..c93d7c48c 100644
--- a/lib/bugsnag/resque.rb
+++ b/lib/bugsnag/resque.rb
@@ -26,7 +26,16 @@ def self.add_failure_backend
     end
 
     def save
-      Bugsnag.auto_notify(exception, {:context => "#{payload['class']}@#{queue}", :payload => payload})
+      Bugsnag.auto_notify(exception, {
+        :context => "#{payload['class']}@#{queue}",
+        :payload => payload,
+        :severity_reason => {
+          :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+          :attributes => {
+            :framework => "Resque"
+          }
+        }
+      })
     end
   end
 end
diff --git a/lib/bugsnag/shoryuken.rb b/lib/bugsnag/shoryuken.rb
index 2a2063179..ab5182442 100644
--- a/lib/bugsnag/shoryuken.rb
+++ b/lib/bugsnag/shoryuken.rb
@@ -18,7 +18,14 @@ def call(_, queue, _, body)
 
         yield
       rescue Exception => ex
-        Bugsnag.auto_notify(ex) unless [Interrupt, SystemExit, SignalException].include?(ex.class)
+        Bugsnag.auto_notify(ex, {
+          :severity_reason => {
+            :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+            :attributes => {
+              :framework => "Shoryuken"
+            }
+          }
+        }) unless [Interrupt, SystemExit, SignalException].include?(ex.class)
         raise
       ensure
         Bugsnag.clear_request_data
diff --git a/lib/bugsnag/sidekiq.rb b/lib/bugsnag/sidekiq.rb
index 3210cbd1e..c411db3d8 100644
--- a/lib/bugsnag/sidekiq.rb
+++ b/lib/bugsnag/sidekiq.rb
@@ -16,7 +16,14 @@ def call(worker, msg, queue)
         yield
       rescue Exception => ex
         raise ex if [Interrupt, SystemExit, SignalException].include? ex.class
-        Bugsnag.auto_notify(ex)
+        Bugsnag.auto_notify(ex, {
+          :severity_reason => {
+            :type => Bugsnag::Notification::UNHANDLED_EXCEPTION_MIDDLEWARE,
+            :attributes => {
+              :framework => "Sidekiq"
+            }
+          }
+        })
         raise
       ensure
         Bugsnag.clear_request_data
diff --git a/spec/integration_spec.rb b/spec/integration_spec.rb
index 64a94dc1c..b3226ec59 100644
--- a/spec/integration_spec.rb
+++ b/spec/integration_spec.rb
@@ -28,8 +28,10 @@
     Dir.chdir(task_fixtures_path) do
       system("bundle exec rake test:crash > /dev/null 2>&1")
     end
-    expect(request["events"][0]["metaData"]["rake_task"]).not_to be_nil
-    expect(request["events"][0]["metaData"]["rake_task"]["name"]).to eq("test:crash")
+
+    result = request()
+    expect(result["events"][0]["metaData"]["rake_task"]).not_to be_nil
+    expect(result["events"][0]["metaData"]["rake_task"]["name"]).to eq("test:crash")
   end
 
   it 'should send notifications over the wire' do
diff --git a/spec/notification_spec.rb b/spec/notification_spec.rb
index 5b50ca18e..92c266021 100644
--- a/spec/notification_spec.rb
+++ b/spec/notification_spec.rb
@@ -113,6 +113,83 @@ def gloops
     }
   end
 
+  it "uses correct unhandled defaults" do
+    Bugsnag.notify(BugsnagTestException.new("It crashed"))
+    
+    expect(Bugsnag).to have_sent_notification{ |payload|
+      event = get_event_from_payload(payload)
+      expect(event["unhandled"]).to be false
+      expect(event["severity"]).to eq("warning")
+      expect(event["severityReason"]).to eq({
+        "type" => "handledException"
+      })
+    }
+  end
+
+  it "sets correct severityReason if severity is modified" do
+    Bugsnag.notify(BugsnagTestException.new("It crashed"), {:severity => "info"})
+
+    expect(Bugsnag).to have_sent_notification{ |payload|
+      event = get_event_from_payload(payload)
+      expect(event["unhandled"]).to be false
+      expect(event["severity"]).to eq("info")
+      expect(event["severityReason"]).to eq({
+        "type" => "userSpecifiedSeverity"
+      })
+    }
+  end
+
+  it "sets correct severityReason if severity is modified in a block" do
+    Bugsnag.notify(BugsnagTestException.new("It crashed")) do |notification|
+      notification.severity = "info"
+    end
+    expect(Bugsnag).to have_sent_notification{ |payload|
+      event = get_event_from_payload(payload)
+      expect(event["unhandled"]).to be false
+      expect(event["severity"]).to eq("info")
+      expect(event["severityReason"]).to eq({
+        "type" => "userCallbackSetSeverity"
+      })
+    }
+  end
+
+  it "sets unhandled and severityReasons through auto_notify" do
+    Bugsnag.auto_notify(BugsnagTestException.new("It crashed"), {
+      :severity_reason => {
+        :type => "unhandledExceptionMiddleware",
+        :attributes => {
+          :framework => "ruby test"
+        }
+      }
+    })
+    expect(Bugsnag).to have_sent_notification{ |payload|
+      event = get_event_from_payload(payload)
+      expect(event["unhandled"]).to be true
+      expect(event["severity"]).to eq("error")
+      expect(event["severityReason"]).to eq({
+        "type" => "unhandledExceptionMiddleware",
+        "attributes" => {
+          "framework" => "ruby test"
+        }
+      })
+    }
+  end
+
+  it "sets correct severity and reason for specific error classes" do
+    Bugsnag.notify(SignalException.new("TERM"))
+    expect(Bugsnag).to have_sent_notification{ |payload|
+      event = get_event_from_payload(payload)
+      expect(event["unhandled"]).to be false
+      expect(event["severity"]).to eq("info")
+      expect(event["severityReason"]).to eq({
+        "type" => "errorClass",
+        "attributes" => {
+          "errorClass" => "SignalException"
+        }
+      })
+    }
+  end
+
   # TODO: nested context
 
   it "accepts tabs in overrides and adds them to metaData" do
@@ -580,12 +657,6 @@ def gloops
     }
   end
 
-  it "does not notify if the exception class is in the default ignore_classes list" do
-    Bugsnag.notify_or_ignore(ActiveRecord::RecordNotFound.new("It crashed"))
-
-    expect(Bugsnag).not_to have_sent_notification
-  end
-
   it "does not notify if the non-default exception class is added to the ignore_classes" do
     Bugsnag.configuration.ignore_classes << "BugsnagTestException"
 
diff --git a/spec/rack_spec.rb b/spec/rack_spec.rb
index 6eb6c9309..353505a74 100644
--- a/spec/rack_spec.rb
+++ b/spec/rack_spec.rb
@@ -32,6 +32,21 @@
 
     end
 
+    it "applies the correct severity reason" do
+      rack_stack.call(rack_env) rescue nil
+
+      expect(Bugsnag).to have_sent_notification{ |payload|
+        event = get_event_from_payload(payload)
+        expect(event["unhandled"]).to be true
+        expect(event["severityReason"]).to eq({
+          "type" => "unhandledExceptionMiddleware",
+          "attributes" => {
+            "framework" => "Rack"
+          }
+        })
+      }
+    end
+
     it "does not deliver an exception if auto_notify is disabled" do
       Bugsnag.configure do |config|
         config.auto_notify = false