mailerの送信元が変わらない

Question

rails チュートリアル11章のメイラーの部分をやっています。applicatoin_mailer.rbのdefault from: の部分を変えてもプレビューで反映されませんでした。

application_mailer.rb

class ApplicationMailer < ActionMailer::Base
  default from: "[e-mail]"
  layout 'mailer'
end

user_mailer.rb

class UserMailer < ApplicationMailer

  def account_activation(user)
    @user = user
    mail to: user.email, subject: "Account activation"
  end

  def password_reset
    @greeting = "Hi"

    mail to: "[e-mail]"
  end
end

その後、user_mailer.rbで個別にfrom:で設定したところ、問題なく動作しました。
なぜdefault from: では反映されなかったのでしょうか?
![

application_mailer.rb

class ApplicationMailer < ActionMailer::Base
  layout 'mailer'
end

user_mailer.rb

class UserMailer < ApplicationMailer

  # Subject can be set in your I18n file at config/locales/en.yml
  # with the following lookup:
  #
  #   en.user_mailer.account_activation.subject
  #
  def account_activation(user)
    @user = user
    mail from: "[e-mail]",
    to: user.email,
    subject: 'Account activation'
  end

  # Subject can be set in your I18n file at config/locales/en.yml
  # with the following lookup:
  #
  #   en.user_mailer.password_reset.subject
  #
  def password_reset
    @greeting = "Hi"

    mail to: "[e-mail]"
  end
end

mailer生成

rails generate mailer UserMailer account_activation password_reset