```ruby
require "active_support/rescuable"
require "action_mailroom/mailbox/callbacks"

class ActionMailroom::Mailbox
  include ActiveSupport::Rescuable, Callbacks

  class << self
    def receive(inbound_email)
      new(inbound_email).perform_processing
    end

    def routing(routes)
      @router = ActionMailroom::Router.new(routes)
    end
  end

  attr_reader :inbound_email
  delegate :mail, to: :inbound_email

  def initialize(inbound_email)
    @inbound_email = inbound_email
  end

  def perform_processing
    inbound_email.processing!

    run_callbacks :process do
      process
    end

    inbound_email.delivered!
  rescue => exception
    inbound_email.failed!
    rescue_with_handler(exception) || raise
  end

  def process
    # Overwrite in subclasses
  end
end
```

Make a note for tying inbound email to exception
user
```ruby
require "active_support/rescuable"
require "action_mailroom/mailbox/callbacks"

class ActionMailroom::Mailbox
  include ActiveSupport::Rescuable, Callbacks

  class << self
    def receive(inbound_email)
      new(inbound_email).perform_processing
    end

    def routing(routes)
      @router = ActionMailroom::Router.new(routes)
    end
  end

  attr_reader :inbound_email
  delegate :mail, to: :inbound_email

  def initialize(inbound_email)
    @inbound_email = inbound_email
  end

  def perform_processing
    inbound_email.processing!

    run_callbacks :process do
      process
    end

    inbound_email.delivered!
  rescue => exception
    inbound_email.failed!
    
    # TODO: Include a reference to the inbound_email in the exception raised so error handling becomes easier
    rescue_with_handler(exception) || raise
  end

  def process
    # Overwrite in subclasses
  end
end
```
assistant