• mail
• action_mailer/collector
• active_support/core_ext/string/inflections
• active_support/core_ext/hash/except
• active_support/core_ext/module/anonymous
• action_mailer/log_subscriber
• action_mailer/rescuable

• 模組 ActionMailer
• 模組 ActionView
• 模組 ActiveSupport
• 模組 Mail
• 類別 ActionMailer::Base
• 類別 ActionMailer::Base::LateAttachmentsProxy