本番環境でメールを受信できない【rails】【SendGrid】

Question

実行環境
ruby 2.6.5
rails 6.0.4.6

deviseの機能を用いてパスワード再発行機能を実装中です。

起こっている問題

サインアップ済ユーザーのメールアドレスをフォームに入力すれば、パスワード変更画面に遷移するためのメールが送信される機能を、こちらの記事を参考にして実装。
ローカル環境では問題なく送信されますが、SendGridを用いた本番環境ではメールを受け取る事ができません。
いくつか試しましたが煮詰まってきた感があるので、皆様のお知恵をお借りしたいです。

config/environments/production.rb

Rails.application.configure do
  # 10000字超えてしまったので関係なさそうなところは省略しています
  config.cache_classes = true

  config.eager_load = true

  config.consider_all_requests_local       = false
  config.action_controller.perform_caching = true

  config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?

  config.assets.compile = true

  config.active_storage.service = :local

  config.log_level = :debug

  config.log_tags = [ :request_id ]

  config.action_mailer.perform_caching = false
  config.action_mailer.default_url_options = {host: 'https://www.アプリ名.herokuapp.com'}
  # Ignore bad email addresses and do not raise email delivery errors.
  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
    config.action_mailer.raise_delivery_errors = false
    config.action_mailer.delivery_method = :smtp
    config.action_mailer.smtp_settings = {
      :user_name => ENV["SENDGRID_USERNAME"],
      :password => ENV["SENDGRID_PASSWORD"],
      :domain => "heroku.com",
      :port => 587,
      :authentication => :plain,
      :enable_starttls_auto => true,
      :address => "smtp.sendgrid.net"
    }

  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
  # the I18n.default_locale when a translation cannot be found).
  config.i18n.fallbacks = true

  # Send deprecation notices to registered listeners.
  config.active_support.deprecation = :notify

  # Use default logging formatter so that PID and timestamp are not suppressed.
  config.log_formatter = ::Logger::Formatter.new

  if ENV["RAILS_LOG_TO_STDOUT"].present?
    logger           = ActiveSupport::Logger.new(STDOUT)
    logger.formatter = config.log_formatter
    config.logger    = ActiveSupport::TaggedLogging.new(logger)
  end

  config.active_record.dump_schema_after_migration = false

ActiveRecord::Middleware::DatabaseSelector::Resolver::Session
end

config/initializer/devise/rb

Devise.setup do |config|
  # ==> Mailer Configuration
  # Configure the e-mail address which will be shown in Devise::Mailer,
  # note that it will be overwritten if you use your own mailer class
  # with default "from" parameter.
  config.mailer_sender = '[e-mail]'

  # Configure the class responsible to send e-mails.
  # config.mailer = 'Devise::Mailer'

  # Configure the parent class responsible to send e-mails.
  # config.parent_mailer = 'ActionMailer::Base'

  require 'devise/orm/active_record'

  config.case_insensitive_keys = [:email]

  config.strip_whitespace_keys = [:email]

  config.skip_session_storage = [:http_auth]

  config.stretches = Rails.env.test? ? 1 : 12

  # Send a notification to the original email when the user's email is changed.
  # config.send_email_changed_notification = false

  # Send a notification email when the user's password is changed.
  # config.send_password_change_notification = false

  config.reconfirmable = true

  config.password_length = 6..128

  config.email_regexp = /\A[^@\s]+@[^@\s]+\z/

  config.reset_password_keys = [:email]

  config.reset_password_within = 6.hours

  config.sign_in_after_reset_password = true

  config.sign_out_via = :delete

end

試してみたこと①

logを確認しました。
私が見る限りでは、正常に送信されているように見受けられます。
実際の挙動も、エラーは起こらず正しい画面に遷移します。
ただし送信先のメールボックスには受信できていませんでした。

2022-03-27T10:59:15.254718+00:00 app[web.1]: D, [2022-03-27T10:59:15.254686 #4] DEBUG -- : [52033afe-b1b1-4c51-b9d3-ca5da5c4c4bb] Date: Sun, 27 Mar 2022 10:59:15 +0000
2022-03-27T10:59:15.254719+00:00 app[web.1]: From: [e-mail]
2022-03-27T10:59:15.254719+00:00 app[web.1]: Reply-To: [e-mail]
2022-03-27T10:59:15.254720+00:00 app[web.1]: To: hoge@hoge
2022-03-27T10:59:15.254721+00:00 app[web.1]: Message-ID: <[e-mail]>
2022-03-27T10:59:15.254721+00:00 app[web.1]: Subject: Reset password instructions
2022-03-27T10:59:15.254721+00:00 app[web.1]: Mime-Version: 1.0
2022-03-27T10:59:15.254722+00:00 app[web.1]: Content-Type: text/html;
2022-03-27T10:59:15.254722+00:00 app[web.1]: charset=UTF-8
2022-03-27T10:59:15.254723+00:00 app[web.1]: Content-Transfer-Encoding: base64
2022-03-27T10:59:15.254723+00:00 app[web.1]: 
2022-03-27T10:59:15.254723+00:00 app[web.1]: 

〜　省略　〜

[52033afe-b1b1-4c51-b9d3-ca5da5c4c4bb] Redirected to https://アプリ名.herokuapp.com/users/sign_in
2022-03-27T10:59:15.256883+00:00 app[web.1]: I, [2022-03-27T10:59:15.256850 #4]  INFO -- : [52033afe-b1b1-4c51-b9d3-ca5da5c4c4bb] Completed 302 Found in 186ms (ActiveRecord: 18.9ms | Allocations: 7951)
2022-03-27T10:59:15.257753+00:00 heroku[router]: at=info method=POST path="/users/password" host=hoge.herokuapp.com request_id=52033afe-b1b1-4c51-b9d3-ca5da5c4c4bb fwd="60.138.7.109" dyno=web.1 connect=0ms service=209ms status=302 bytes=1334 protocol=https
2022-03-27T10:59:15.429519+00:00 app[web.1]: I, [2022-03-27T10:59:15.429457 #4]  INFO -- : [a5eb24d1-241d-4c2c-affd-a9c45bb38172] Started GET "/users/sign_in" for 60.138.7.109 at 2022-03-27 10:59:15 +0000
2022-03-27T10:59:15.430249+00:00 app[web.1]: I, [2022-03-27T10:59:15.430200 #4]  INFO -- : [a5eb24d1-241d-4c2c-affd-a9c45bb38172] Processing by Devise::SessionsController#new as HTML
2022-03-27T10:59:15.431515+00:00 app[web.1]: I, [2022-03-27T10:59:15.431471 #4]  INFO -- : [a5eb24d1-241d-4c2c-affd-a9c45bb38172]   Rendering devise/sessions/new.html.erb within layouts/application
2022-03-27T10:59:15.433360+00:00 app[web.1]: I, [2022-03-27T10:59:15.433317 #4]  INFO -- : [a5eb24d1-241d-4c2c-affd-a9c45bb38172]   Rendered devise/shared/_links.html.erb (Duration: 0.2ms | Allocations: 134)
2022-03-27T10:59:15.433408+00:00 app[web.1]: I, [2022-03-27T10:59:15.433384 #4]  INFO -- : [a5eb24d1-241d-4c2c-affd-a9c45bb38172]   Rendered devise/sessions/new.html.erb within layouts/application (Duration: 1.8ms | Allocations: 1232)
2022-03-27T10:59:15.433918+00:00 app[web.1]: I, [2022-03-27T10:59:15.433882 #4]  INFO -- : [a5eb24d1-241d-4c2c-affd-a9c45bb38172] Completed 200 OK in 4ms (Views: 2.6ms | ActiveRecord: 0.0ms | Allocations: 2178)
2022-03-27T10:59:15.434682+00:00 heroku[router]: at=info method=GET path="/users/sign_in" host=アプリ名.herokuapp.com request_id=a5eb24d1-241d-4c2c-affd-a9c45bb38172 fwd="60.138.7.109" dyno=web.1 connect=0ms service=6ms status=200 bytes=3209 protocol=https
2022-03-27T11:33:29.968366+00:00 heroku[web.1]: Idling
2022-03-27T11:33:29.971010+00:00 heroku[web.1]: State changed from up to down
2022-03-27T11:33:30.720213+00:00 heroku[web.1]: Stopping all processes with SIGTERM
2022-03-27T11:33:30.764200+00:00 app[web.1]: - Gracefully stopping, waiting for requests to finish

試してみたこと②

ローカル環境では正常にGoogleメールが送信できている、という事で、
SendGridに問題があるのではと思い問い合わせてみたら、アカウントを凍結されていたようです。
2,3メールをやりとりしてアカウントが使えるようになったので、

git push heroku master
heroku run rails db:migrate

で再度メールを送信しましたが、受信できませんでした。

見づらいファイルばかり貼り付けて面目ないです。
お目汚ししてしまい恐縮ですが、回答いただければと思います。

Answer 1

根本的な解決には至りませんでしたが、こちらの記事を参考にしてMailgunに乗り換えてみたところ、晴れてメールが届きました！

  config.action_mailer.perform_caching = false
  config.action_mailer.default_url_options = {host: 'https://www.mammon-quest.herokuapp.com'}
  # Ignore bad email addresses and do not raise email delivery errors.
  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
    config.action_mailer.raise_delivery_errors = false
    config.action_mailer.delivery_method = :smtp
    config.action_mailer.smtp_settings = {
      :port => ENV['MAILGUN_SMTP_PORT'],
      :address => ENV['MAILGUN_SMTP_SERVER'],
      :user_name => ENV['MAILGUN_SMTP_LOGIN'],
      :password => ENV['MAILGUN_SMTP_PASSWORD'],
      :domain => 'heroku.com',
      :authentication => :plain,
    }