Add latest changes from gitlab-org/gitlab@16-0-stable-eev16.0.0-rc42

8 files changed, 387 insertions, 71 deletions

diff --git a/app/mailers/emails/issues.rb b/app/mailers/emails/issues.rb
index 58843435fa0..0328d262dc7 100644
--- a/app/mailers/emails/issues.rb
+++ b/app/mailers/emails/issues.rb
@@ -5,18 +5,32 @@ module Emails
     def new_issue_email(recipient_id, issue_id, reason = nil)
       setup_issue_mail(issue_id, recipient_id)
 
-      mail_new_thread(@issue, issue_thread_options(@issue.author_id, reason))
+      mail_new_thread(
+        @issue,
+        issue_thread_options(
+          @issue.author_id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
 
     def issue_due_email(recipient_id, issue_id, reason = nil)
       setup_issue_mail(issue_id, recipient_id)
 
-      mail_answer_thread(@issue, issue_thread_options(@issue.author_id, reason))
+      mail_answer_thread(@issue, issue_thread_options(@issue.author_id, reason, confidentiality: @issue.confidential?))
     end
 
     def new_mention_in_issue_email(recipient_id, issue_id, updated_by_user_id, reason = nil)
       setup_issue_mail(issue_id, recipient_id)
-      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, reason))
+      mail_answer_thread(
+        @issue,
+        issue_thread_options(
+          updated_by_user_id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
 
     # rubocop: disable CodeReuse/ActiveRecord
@@ -26,7 +40,14 @@ module Emails
       @previous_assignees = []
       @previous_assignees = User.where(id: previous_assignee_ids) if previous_assignee_ids.any?
 
-      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, reason))
+      mail_answer_thread(
+        @issue,
+        issue_thread_options(
+          updated_by_user_id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
     # rubocop: enable CodeReuse/ActiveRecord
 
@@ -35,7 +56,14 @@ module Emails
 
       @updated_by = User.find(updated_by_user_id)
 
-      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, reason))
+      mail_answer_thread(
+        @issue,
+        issue_thread_options(
+          updated_by_user_id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
 
     def relabeled_issue_email(recipient_id, issue_id, label_names, updated_by_user_id, reason = nil)
@@ -43,13 +71,27 @@ module Emails
 
       @label_names = label_names
       @labels_url = project_labels_url(@project)
-      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, reason))
+      mail_answer_thread(
+        @issue,
+        issue_thread_options(
+          updated_by_user_id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
 
     def removed_milestone_issue_email(recipient_id, issue_id, updated_by_user_id, reason = nil)
       setup_issue_mail(issue_id, recipient_id)
 
-      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, reason))
+      mail_answer_thread(
+        @issue,
+        issue_thread_options(
+          updated_by_user_id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
 
     def changed_milestone_issue_email(recipient_id, issue_id, milestone, updated_by_user_id, reason = nil)
@@ -57,9 +99,14 @@ module Emails
 
       @milestone = milestone
       @milestone_url = milestone_url(@milestone)
-      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, reason).merge({
-        template_name: 'changed_milestone_email'
-      }))
+      mail_answer_thread(
+        @issue,
+        issue_thread_options(
+          updated_by_user_id,
+          reason,
+          confidentiality: @issue.confidential?
+        ).merge({ template_name: 'changed_milestone_email' })
+      )
     end
 
     def issue_status_changed_email(recipient_id, issue_id, status, updated_by_user_id, reason = nil)
@@ -67,7 +114,14 @@ module Emails
 
       @issue_status = status
       @updated_by = User.find(updated_by_user_id)
-      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, reason))
+      mail_answer_thread(
+        @issue,
+        issue_thread_options(
+          updated_by_user_id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
 
     def issue_moved_email(recipient, issue, new_issue, updated_by_user, reason = nil)
@@ -76,7 +130,14 @@ module Emails
       @new_issue = new_issue
       @new_project = new_issue.project
       @can_access_project = recipient.can?(:read_project, @new_project)
-      mail_answer_thread(issue, issue_thread_options(updated_by_user.id, reason))
+      mail_answer_thread(
+        issue,
+        issue_thread_options(
+          updated_by_user.id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
 
     def issue_cloned_email(recipient, issue, new_issue, updated_by_user, reason = nil)
@@ -86,7 +147,14 @@ module Emails
       @issue = issue
       @new_issue = new_issue
       @can_access_project = recipient.can?(:read_project, @new_issue.project)
-      mail_answer_thread(issue, issue_thread_options(updated_by_user.id, reason))
+      mail_answer_thread(
+        issue,
+        issue_thread_options(
+          updated_by_user.id,
+          reason,
+          confidentiality: @issue.confidential?
+        )
+      )
     end
 
     def import_issues_csv_email(user_id, project_id, results)
@@ -100,18 +168,7 @@ module Emails
     end
 
     def issues_csv_email(user, project, csv_data, export_status)
-      @project = project
-      @count = export_status.fetch(:rows_expected)
-      @written_count = export_status.fetch(:rows_written)
-      @truncated = export_status.fetch(:truncated)
-      @size_limit = ActiveSupport::NumberHelper
-        .number_to_human_size(ExportCsv::BaseService::TARGET_FILESIZE)
-
-      filename = "#{project.full_path.parameterize}_issues_#{Date.today.iso8601}.csv"
-      attachments[filename] = { content: csv_data, mime_type: 'text/csv' }
-      email_with_layout(
-        to: user.notification_email_for(@project.group),
-        subject: subject("Exported issues"))
+      csv_email(user, project, csv_data, export_status, 'issues')
     end
 
     private
@@ -126,12 +183,14 @@ module Emails
       @sent_notification = SentNotification.record(@issue, recipient_id, reply_key)
     end
 
-    def issue_thread_options(sender_id, reason)
+    def issue_thread_options(sender_id, reason, confidentiality: false)
+      confidentiality = false if confidentiality.nil?
       {
         from: sender(sender_id),
         to: @recipient.notification_email_for(@project.group),
         subject: subject("#{@issue.title} (##{@issue.iid})"),
-        'X-GitLab-NotificationReason' => reason
+        'X-GitLab-NotificationReason' => reason,
+        'X-GitLab-ConfidentialIssue' => confidentiality
       }
     end
   end
diff --git a/app/mailers/emails/profile.rb b/app/mailers/emails/profile.rb
index 5b1750400d8..54a4c4be6a8 100644
--- a/app/mailers/emails/profile.rb
+++ b/app/mailers/emails/profile.rb
@@ -153,7 +153,7 @@ module Emails
       Gitlab::I18n.with_locale(@user.preferred_language) do
         email_with_layout(
           to: @user.notification_email_or_default,
-          subject: subject(_("Attempted sign in to %{host} using a wrong two-factor authentication code") % { host: Gitlab.config.gitlab.host }))
+          subject: subject(_("Attempted sign in to %{host} using an incorrect verification code") % { host: Gitlab.config.gitlab.host }))
       end
     end
 
@@ -177,6 +177,19 @@ module Emails
         mail_with_locale(to: @user.notification_email_or_default, subject: subject(_("New email address added")))
       end
     end
+
+    def new_achievement_email(user, achievement)
+      return unless user&.active?
+
+      @user = user
+      @achievement = achievement
+
+      Gitlab::I18n.with_locale(@user.preferred_language) do
+        email_with_layout(
+          to: @user.notification_email_or_default,
+          subject: subject(s_("Achievements|%{namespace_full_path} awarded you the %{achievement_name} achievement") % { namespace_full_path: @achievement.namespace.full_path, achievement_name: @achievement.name }))
+      end
+    end
   end
 end
 
diff --git a/app/mailers/emails/projects.rb b/app/mailers/emails/projects.rb
index 4bb624c27e9..63eb4eb8fd8 100644
--- a/app/mailers/emails/projects.rb
+++ b/app/mailers/emails/projects.rb
@@ -7,29 +7,37 @@ module Emails
       @project = Project.find project_id
       @target_url = project_url(@project)
       @old_path_with_namespace = old_path_with_namespace
-      mail_with_locale(to: @user.notification_email_for(@project.group),
-                       subject: subject("Project was moved"))
+      mail_with_locale(
+        to: @user.notification_email_for(@project.group),
+        subject: subject("Project was moved")
+      )
     end
 
     def project_was_exported_email(current_user, project)
       @project = project
-      mail_with_locale(to: current_user.notification_email_for(project.group),
-                       subject: subject("Project was exported"))
+      mail_with_locale(
+        to: current_user.notification_email_for(project.group),
+        subject: subject("Project was exported")
+      )
     end
 
     def project_was_not_exported_email(current_user, project, errors)
       @project = project
       @errors = errors
-      mail_with_locale(to: current_user.notification_email_for(@project.group),
-                       subject: subject("Project export error"))
+      mail_with_locale(
+        to: current_user.notification_email_for(@project.group),
+        subject: subject("Project export error")
+      )
     end
 
     def repository_cleanup_success_email(project, user)
       @project = project
       @user = user
 
-      mail_with_locale(to: user.notification_email_for(project.group),
-                       subject: subject("Project cleanup has completed"))
+      mail_with_locale(
+        to: user.notification_email_for(project.group),
+        subject: subject("Project cleanup has completed")
+      )
     end
 
     def repository_cleanup_failure_email(project, user, error)
@@ -52,9 +60,11 @@ module Emails
       add_project_headers
       headers['X-GitLab-Author'] = @message.author_username
 
-      mail_with_locale(from: sender(@message.author_id, send_from_user_email: @message.send_from_committer_email?),
-                       reply_to: @message.reply_to,
-                       subject: @message.subject)
+      mail_with_locale(
+        from: sender(@message.author_id, send_from_user_email: @message.send_from_committer_email?),
+        reply_to: @message.reply_to,
+        subject: @message.subject
+      )
     end
 
     def prometheus_alert_fired_email(project, user, alert)
diff --git a/app/mailers/emails/service_desk.rb b/app/mailers/emails/service_desk.rb
index 1295f978049..c627f4633e4 100644
--- a/app/mailers/emails/service_desk.rb
+++ b/app/mailers/emails/service_desk.rb
@@ -20,15 +20,24 @@ module Emails
         sender_name: @service_desk_setting&.outgoing_name,
         sender_email: service_desk_sender_email_address
       )
-      options = service_desk_options(email_sender, 'thank_you', @issue.external_author)
-                  .merge(subject: "Re: #{subject_base}")
 
-      inject_service_desk_custom_email(mail_new_thread(@issue, options))
+      options = {
+        from: email_sender,
+        to: @issue.external_author,
+        subject: "Re: #{subject_base}",
+        **service_desk_template_content_options('thank_you')
+      }
+
+      mail_new_thread(@issue, options)
+      inject_service_desk_custom_email
     end
 
     def service_desk_new_note_email(issue_id, note_id, recipient)
       @note = Note.find(note_id)
+
       setup_service_desk_mail(issue_id)
+      # Prepare uploads for text replacement in markdown content
+      setup_service_desk_attachments
 
       email_sender = sender(
         @note.author_id,
@@ -36,11 +45,74 @@ module Emails
         sender_email: service_desk_sender_email_address
       )
 
-      add_uploads_as_attachments if Feature.enabled?(:service_desk_new_note_email_native_attachments, @note.project)
-      options = service_desk_options(email_sender, 'new_note', recipient)
-                  .merge(subject: subject_base)
+      options = {
+        from: email_sender,
+        to: recipient,
+        subject: subject_base,
+        **service_desk_template_content_options('new_note')
+      }
 
-      inject_service_desk_custom_email(mail_answer_thread(@issue, options))
+      mail_answer_thread(@issue, options)
+      # Add attachments after email init to guide ActiveMailer
+      # to choose the correct multipart content types
+      add_uploads_as_attachments
+      inject_service_desk_custom_email
+    end
+
+    def service_desk_custom_email_verification_email(service_desk_setting)
+      @service_desk_setting = service_desk_setting
+
+      email_sender = sender(
+        User.support_bot.id,
+        send_from_user_email: false,
+        sender_name: @service_desk_setting.outgoing_name,
+        sender_email: @service_desk_setting.custom_email
+      )
+
+      @verification_token = @service_desk_setting.custom_email_verification.token
+
+      subject = format(s_("Notify|Verify custom email address %{email} for %{project_name}"),
+        email: @service_desk_setting.custom_email,
+        project_name: @service_desk_setting.project.name
+      )
+
+      options = {
+        from: email_sender,
+        to: @service_desk_setting.custom_email_address_for_verification,
+        subject: subject,
+        content_type: "text/plain; charset=UTF-8"
+      }
+      # Outgoing emails from GitLab usually have this set to true.
+      # Service Desk email ingestion ignores auto generated emails.
+      headers["Auto-Submitted"] = "no"
+
+      mail_with_locale(options)
+      inject_service_desk_custom_email(force: true)
+    end
+
+    def service_desk_verification_triggered_email(service_desk_setting, recipient)
+      @service_desk_setting = service_desk_setting
+      @triggerer = @service_desk_setting.custom_email_verification.triggerer
+      @smtp_address = @service_desk_setting.custom_email_credential.smtp_address
+
+      subject = format(s_("Notify|Verification for custom email %{email} for %{project_name} triggered"),
+        email: @service_desk_setting.custom_email,
+        project_name: @service_desk_setting.project.name
+      )
+
+      email_with_layout(to: recipient, subject: subject)
+    end
+
+    def service_desk_verification_result_email(service_desk_setting, recipient)
+      @service_desk_setting = service_desk_setting
+      @verification = @service_desk_setting.custom_email_verification
+
+      subject = format(s_("Notify|Verification result for custom email %{email} for %{project_name}"),
+        email: @service_desk_setting.custom_email,
+        project_name: @service_desk_setting.project.name
+      )
+
+      email_with_layout(to: recipient, subject: subject)
     end
 
     private
@@ -55,22 +127,20 @@ module Emails
       @sent_notification = SentNotification.record(@issue, @support_bot.id, reply_key)
     end
 
-    def service_desk_options(email_sender, email_type, recipient)
-      {
-        from: email_sender,
-        to: recipient
-      }.tap do |options|
-        next unless template_body = template_content(email_type)
+    def service_desk_template_content_options(email_type)
+      return {} unless template_body = template_content(email_type)
 
-        options[:body] = template_body
-        options[:content_type] = 'text/html' unless attachments.present?
-      end
+      {
+        body: template_body,
+        content_type: 'text/html; charset=UTF-8'
+      }
     end
 
-    def inject_service_desk_custom_email(mail)
-      return mail unless service_desk_custom_email_enabled?
+    def inject_service_desk_custom_email(force: false)
+      return mail if !service_desk_custom_email_enabled? && !force
+      return mail unless @service_desk_setting.custom_email_credential.present?
 
-      mail.delivery_method(::Mail::SMTP, @service_desk_setting.custom_email_delivery_options)
+      mail.delivery_method(::Mail::SMTP, @service_desk_setting.custom_email_credential.delivery_options)
     end
 
     def service_desk_custom_email_enabled?
@@ -101,6 +171,7 @@ module Emails
         .gsub(/%\{\s*ISSUE_ID\s*\}/, issue_id)
         .gsub(/%\{\s*ISSUE_PATH\s*\}/, issue_path)
         .gsub(/%\{\s*NOTE_TEXT\s*\}/, note_text)
+        .gsub(/%\{\s*ISSUE_DESCRIPTION\s*\}/, issue_description)
         .gsub(/%\{\s*SYSTEM_HEADER\s*\}/, text_header_message.to_s)
         .gsub(/%\{\s*SYSTEM_FOOTER\s*\}/, text_footer_message.to_s)
         .gsub(/%\{\s*UNSUBSCRIBE_URL\s*\}/, unsubscribe_sent_notification_url(@sent_notification))
@@ -119,24 +190,40 @@ module Emails
       @note&.note.to_s
     end
 
+    def issue_description
+      @issue.description_html.to_s
+    end
+
     def subject_base
       "#{@issue.title} (##{@issue.iid})"
     end
 
-    def add_uploads_as_attachments
+    def setup_service_desk_attachments
+      @uploads_to_attach = []
+      # Filepaths we should replace in markdown content
+      @uploads_as_attachments = []
+
+      return unless Feature.enabled?(:service_desk_new_note_email_native_attachments, @note.project)
+
       uploaders = find_uploaders_for(@note)
-      return unless uploaders.present?
+      return if uploaders.nil?
       return if uploaders.sum(&:size) > EMAIL_ATTACHMENTS_SIZE_LIMIT
 
-      @uploads_as_attachments = []
       uploaders.each do |uploader|
-        attachments[uploader.filename] = uploader.read
+        @uploads_to_attach << { filename: uploader.filename, content: uploader.read }
         @uploads_as_attachments << "#{uploader.secret}/#{uploader.filename}"
       rescue StandardError => e
         Gitlab::ErrorTracking.track_exception(e, project_id: @note.project.id)
       end
     end
 
+    def add_uploads_as_attachments
+      # We read the uploads before in setup_service_desk_attachments, so let's just add them
+      @uploads_to_attach.each do |upload|
+        mail.add_file(filename: upload[:filename], content: upload[:content])
+      end
+    end
+
     def find_uploaders_for(note)
       uploads = FileUploader::MARKDOWN_PATTERN.scan(note.note)
       return unless uploads.present?
diff --git a/app/mailers/emails/shared.rb b/app/mailers/emails/shared.rb
new file mode 100644
index 00000000000..09876c0960a
--- /dev/null
+++ b/app/mailers/emails/shared.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Emails
+  module Shared
+    def csv_email(user, project, csv_data, export_status, type)
+      @project = project
+      @count = export_status.fetch(:rows_expected)
+      @written_count = export_status.fetch(:rows_written)
+      @truncated = export_status.fetch(:truncated)
+      @size_limit = ActiveSupport::NumberHelper
+        .number_to_human_size(ExportCsv::BaseService::TARGET_FILESIZE)
+
+      filename = "#{project.full_path.parameterize}_#{type}_#{Date.today.iso8601}.csv"
+      attachments[filename] = { content: csv_data, mime_type: 'text/csv' }
+      email_with_layout(
+        to: user.notification_email_for(@project.group),
+        subject: subject("Exported #{type.humanize.downcase}"))
+    end
+  end
+end
diff --git a/app/mailers/emails/work_items.rb b/app/mailers/emails/work_items.rb
new file mode 100644
index 00000000000..b14111c94eb
--- /dev/null
+++ b/app/mailers/emails/work_items.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Emails
+  module WorkItems
+    def import_work_items_csv_email(user_id, project_id, results)
+      @user = User.find(user_id)
+      @project = Project.find(project_id)
+      @results = results
+
+      email_with_layout(
+        to: @user.notification_email_for(@project.group),
+        subject: subject('Imported work items'))
+    end
+
+    def export_work_items_csv_email(user, project, csv_data, export_status)
+      csv_email(user, project, csv_data, export_status, 'work_items')
+    end
+  end
+end
diff --git a/app/mailers/notify.rb b/app/mailers/notify.rb
index 28ef6d8d6c6..036a0fc012e 100644
--- a/app/mailers/notify.rb
+++ b/app/mailers/notify.rb
@@ -7,6 +7,7 @@ class Notify < ApplicationMailer
   include ReminderEmailsHelper
   include IssuablesHelper
 
+  include Emails::Shared
   include Emails::Issues
   include Emails::MergeRequests
   include Emails::Notes
@@ -25,6 +26,7 @@ class Notify < ApplicationMailer
   include Emails::AdminNotification
   include Emails::IdentityVerification
   include Emails::Imports
+  include Emails::WorkItems
 
   helper TimeboxesHelper
   helper MergeRequestsHelper
@@ -39,11 +41,12 @@ class Notify < ApplicationMailer
   helper InProductMarketingHelper
 
   def test_email(recipient_email, subject, body)
-    mail_with_locale(to: recipient_email,
-                     subject: subject,
-                     body: body.html_safe,
-                     content_type: 'text/html'
-                    )
+    mail_with_locale(
+      to: recipient_email,
+      subject: subject,
+      body: body.html_safe,
+      content_type: 'text/html'
+    )
   end
 
   # Splits "gitlab.corp.company.com" up into "gitlab.corp.company.com",
@@ -130,8 +133,8 @@ class Notify < ApplicationMailer
 
     @reason = headers['X-GitLab-NotificationReason']
 
-    if Gitlab::IncomingEmail.enabled? && @sent_notification
-      headers['Reply-To'] = Mail::Address.new(Gitlab::IncomingEmail.reply_address(reply_key)).tap do |address|
+    if Gitlab::Email::IncomingEmail.enabled? && @sent_notification
+      headers['Reply-To'] = Mail::Address.new(Gitlab::Email::IncomingEmail.reply_address(reply_key)).tap do |address|
         address.display_name = reply_display_name(model)
       end
 
@@ -219,8 +222,8 @@ class Notify < ApplicationMailer
     return unless !@labels_url && @sent_notification && @sent_notification.unsubscribable?
 
     list_unsubscribe_methods = [unsubscribe_sent_notification_url(@sent_notification, force: true)]
-    if Gitlab::IncomingEmail.enabled? && Gitlab::IncomingEmail.supports_wildcard?
-      list_unsubscribe_methods << "mailto:#{Gitlab::IncomingEmail.unsubscribe_address(reply_key)}"
+    if Gitlab::Email::IncomingEmail.enabled? && Gitlab::Email::IncomingEmail.supports_wildcard?
+      list_unsubscribe_methods << "mailto:#{Gitlab::Email::IncomingEmail.unsubscribe_address(reply_key)}"
     end
 
     headers['List-Unsubscribe'] = list_unsubscribe_methods.map { |e| "<#{e}>" }.join(',')
diff --git a/app/mailers/previews/notify_preview.rb b/app/mailers/previews/notify_preview.rb
index 7ed594bf571..d91f69cdd4b 100644
--- a/app/mailers/previews/notify_preview.rb
+++ b/app/mailers/previews/notify_preview.rb
@@ -60,6 +60,14 @@ class NotifyPreview < ActionMailer::Preview
     end
   end
 
+  def access_token_created_email
+    Notify.access_token_created_email(user, 'token_name').message
+  end
+
+  def access_token_revoked_email
+    Notify.access_token_revoked_email(user, 'token_name').message
+  end
+
   def new_mention_in_merge_request_email
     Notify.new_mention_in_merge_request_email(user.id, merge_request.id, user.id).message
   end
@@ -84,6 +92,10 @@ class NotifyPreview < ActionMailer::Preview
     Notify.import_issues_csv_email(user.id, project.id, { success: 3, errors: [5, 6, 7], valid_file: true })
   end
 
+  def import_work_items_csv_email
+    Notify.import_work_items_csv_email(user.id, project.id, { success: 4, error_lines: [2, 3, 4], parse_error: false })
+  end
+
   def issues_csv_email
     Notify.issues_csv_email(user, project, '1997,Ford,E350', { truncated: false, rows_expected: 3, rows_written: 3 }).message
   end
@@ -201,6 +213,52 @@ class NotifyPreview < ActionMailer::Preview
     Notify.service_desk_thank_you_email(issue.id).message
   end
 
+  def service_desk_custom_email_verification_email
+    cleanup do
+      setup_service_desk_custom_email_objects
+
+      Notify.service_desk_custom_email_verification_email(service_desk_setting).message
+    end
+  end
+
+  def service_desk_verification_triggered_email
+    cleanup do
+      setup_service_desk_custom_email_objects
+
+      Notify.service_desk_verification_triggered_email(service_desk_setting, 'owner@example.com').message
+    end
+  end
+
+  def service_desk_verification_result_email_for_verified_state
+    cleanup do
+      setup_service_desk_custom_email_objects
+
+      custom_email_verification.mark_as_finished!
+
+      Notify.service_desk_verification_result_email(service_desk_setting, 'owner@example.com').message
+    end
+  end
+
+  def service_desk_verification_result_email_for_incorrect_token_error
+    service_desk_verification_result_email_for_error_state(error: :incorrect_token)
+  end
+
+  def service_desk_verification_result_email_for_incorrect_from_error
+    service_desk_verification_result_email_for_error_state(error: :incorrect_from)
+  end
+
+  def service_desk_verification_result_email_for_mail_not_received_within_timeframe_error
+    service_desk_verification_result_email_for_error_state(error: :mail_not_received_within_timeframe)
+  end
+
+  def service_desk_verification_result_email_for_invalid_credentials_error
+    service_desk_verification_result_email_for_error_state(error: :invalid_credentials)
+  end
+
+  def service_desk_verification_result_email_for_smtp_host_issue_error
+    service_desk_verification_result_email_for_error_state(error: :smtp_host_issue)
+  end
+
   def merge_when_pipeline_succeeds_email
     Notify.merge_when_pipeline_succeeds_email(user.id, merge_request.id, user.id).message
   end
@@ -235,6 +293,53 @@ class NotifyPreview < ActionMailer::Preview
     @project ||= Project.first
   end
 
+  def service_desk_verification_result_email_for_error_state(error:)
+    cleanup do
+      setup_service_desk_custom_email_objects
+
+      custom_email_verification.mark_as_failed!(error)
+
+      Notify.service_desk_verification_result_email(service_desk_setting, 'owner@example.com').message
+    end
+  end
+
+  def setup_service_desk_custom_email_objects
+    # Call accessors to ensure objects have been created
+    custom_email_credential
+    custom_email_verification
+
+    # Update associations in projects, because we access
+    # custom_email_credential and custom_email_verification via project
+    project.reset
+  end
+
+  def custom_email_verification
+    @custom_email_verification ||= project.service_desk_custom_email_verification || ServiceDesk::CustomEmailVerification.create!(
+      project: project,
+      token: 'XXXXXXXXXXXX',
+      triggerer: user,
+      triggered_at: Time.current,
+      state: 'started'
+    )
+  end
+
+  def custom_email_credential
+    @custom_email_credential ||= project.service_desk_custom_email_credential || ServiceDesk::CustomEmailCredential.create!(
+      project: project,
+      smtp_address: 'smtp.gmail.com', # Use gmail, because Gitlab::UrlBlocker resolves DNS
+      smtp_port: 587,
+      smtp_username: 'user@gmail.com',
+      smtp_password: 'supersecret'
+    )
+  end
+
+  def service_desk_setting
+    @service_desk_setting ||= project.service_desk_setting || ServiceDeskSetting.create!(
+      project: project,
+      custom_email: 'user@gmail.com'
+    )
+  end
+
   def issue
     @issue ||= project.issues.first
   end