```ruby
# This file is part of Mconf-Web, a web application that provides access
# to the Mconf webconferencing system. Copyright (C) 2010-2012 Mconf
#
# This file is licensed under the Affero General Public License version
# 3 or later. See the LICENSE file.

# Initializes the ExceptionNotifier using the information stored in the current Site
# Works only in production
if Rails.env.production? and Site.table_exists?
  site = Site.current
  if site.respond_to?(:exception_notifications) && site.exception_notifications
    recipients = site.exception_notifications_email.split(/[\s,;]/).reject(&:empty?) # accepts " ", "," and ";" as separators
    Mconf::Application.config.middleware.use ExceptionNotifier,
      :email_prefix => site.exception_notifications_prefix + " ",
      :sender_address => %("#{site.name}" <#{site.email}>),
      :exception_recipients => recipients
  end
end
```

Refactor exception notifier's init: fix errors if Site doesn't have all columns
user
```ruby
# This file is part of Mconf-Web, a web application that provides access
# to the Mconf webconferencing system. Copyright (C) 2010-2012 Mconf
#
# This file is licensed under the Affero General Public License version
# 3 or later. See the LICENSE file.

def check_conditions
  if Rails.env.production? and Site.table_exists?
    site = Site.current
    return site &&
      site.respond_to?(:exception_notifications) &&
      site.exception_notifications
  else
    false
  end
end

def get_sender_address
  site = Site.current
  if site.respond_to?(:name) && site.respond_to?(:email)
    %("#{site.name}" <#{site.email}>)
  else
    "Undefined"
  end
end

# Initializes the ExceptionNotifier using the information stored in the current Site
# Works only in production
def configure_exception_notifier
  site = Site.current

  # accepts " ", "," and ";" as separators
  recvs = site.exception_notifications_email.split(/[\s,;]/).reject(&:empty?)

  Mconf::Application.config.middleware.use ExceptionNotifier,
  :email_prefix => site.exception_notifications_prefix + " ",
  :sender_address => get_sender_address(),
  :exception_recipients => recvs
end

if check_conditions()
  configure_exception_notifier()
end
```
assistant