mastodon/app/mailers/application_mailer.rb

# frozen_string_literal: true

class ApplicationMailer < ActionMailer::Base
  default from: ENV.fetch('SMTP_FROM_ADDRESS') { 'notifications@localhost' }
  layout 'mailer'
  helper :instance

  protected

  def locale_for_account(account)
    I18n.with_locale(account.user_locale || I18n.default_locale) do
      yield
    end
  end
end