Generate mailer message id to fix spam issue

yeo · Dec 31, 2019 · ae99d4f · ae99d4f
1 parent 765d536
commit ae99d4f
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Showing 2 changed files with 6 additions and 3 deletions.
diff --git a/app/mailers/application_mailer.rb b/app/mailers/application_mailer.rb
@@ -1,9 +1,12 @@
 # frozen_string_literal: true
 
 class ApplicationMailer < ActionMailer::Base
- # TODO: Remove hard code domain
+ # RFC 2822 requires that message-id match the from domain
+ # We're using SendGrid and the from domain is convert into [sendgrid-id]-[our-selected-subdomain]
+ DOMAIN = Rails.application.config.action_mailer.smtp_settings[:from].split("@").last
  default(from: Rails.application.config.action_mailer.smtp_settings[:from],
- 'Message-ID' => -> { "#{Digest::SHA2.hexdigest(Time.now.to_i.to_s)}@noty.im" })
+ reply_to: 'hello@noty.im',
+ 'Message-ID' => -> { "#{Digest::SHA2.hexdigest(Time.now.to_i.to_s)}@#{DOMAIN}" })
 
  layout 'mailer'
 end
diff --git a/config/initializers/smtp.rb b/config/initializers/smtp.rb
@@ -3,7 +3,7 @@
 Rails.application.config.action_mailer.smtp_settings = {
  authentication: :plain,
  address: ENV['SMTP_ADDRESS'] || Rails.application.credentials[:SMTP_ADDRESS],
- from: ENV.fetch('SMTP_FROM', 'oncall@alert.noty.im'),
+ from: ENV.fetch('SMTP_FROM', 'oncall@em4957.alert.noty.im'),
  port: 587,
  domain: ENV['SMTP_DOMAIN'] || Rails.application.credentials[:SMTP_DOMAIN],
  user_name: ENV['SMTP_USER_NAME'] || Rails.application.credentials[:SMTP_USER_NAME],