style(rubocop): Layout/LineLength

app/controllers/servers_controller.rb

@@ -43,7 +43,12 @@ class ServersController < ApplicationController
 
   def update
     extra_params = [:spam_threshold, :spam_failure_threshold, :postmaster_address]
-    extra_params += [:send_limit, :allow_sender, :privacy_mode, :log_smtp_data, :outbound_spam_threshold, :message_retention_days, :raw_message_retention_days, :raw_message_retention_size] if current_user.admin?
+
+    if current_user.admin?
+      extra_params += [:send_limit, :allow_sender, :privacy_mode, :log_smtp_data, :outbound_spam_threshold,
+                       :message_retention_days, :raw_message_retention_days, :raw_message_retention_size]
+    end
+
     if @server.update(safe_params(*extra_params))
       redirect_to_with_json organization_server_path(organization, @server), notice: "Server settings have been updated"
     else

app/controllers/user_controller.rb

@@ -71,7 +71,9 @@ class UserController < ApplicationController
 
     if @user.save
       if email_changed
-        redirect_to_with_json verify_path(return_to: settings_path), notice: "Your settings have been updated successfully. As you've changed, your e-mail address you'll need to verify it before you can continue."
+        redirect_to_with_json verify_path(return_to: settings_path),
+                              notice: "Your settings have been updated successfully. As you've changed, your e-mail " \
+                                      "address you'll need to verify it before you can continue."
       else
         redirect_to_with_json settings_path, notice: "Your settings have been updated successfully."
       end

app/jobs/unqueue_message_job.rb

@@ -2,6 +2,7 @@
 
 class UnqueueMessageJob < Postal::Job
 
+  # rubocop:disable Layout/LineLength
   def perform
     if original_message = QueuedMessage.find_by_id(params["id"])
       if original_message.acquire_lock
@@ -430,7 +431,12 @@ class UnqueueMessageJob < Postal::Job
               Sentry.capture_exception(e, extra: { job_id: self.id, server_id: queued_message.server_id, message_id: queued_message.message_id })
             end
             if queued_message.message
-              queued_message.message.create_delivery("Error", details: "An internal error occurred while sending this message. This message will be retried automatically. If this persists, contact support for assistance.", output: "#{e.class}: #{e.message}", log_id: "J-#{self.id}")
+              queued_message.message.create_delivery("Error",
+                                                     details: "An internal error occurred while sending " \
+                                                              "this message. This message will be retried " \
+                                                              "automatically.",
+                                                     output: "#{e.class}: #{e.message}", log_id: "J-#{self.id}"
+                                                    )
             end
           end
         end
@@ -448,6 +454,7 @@ class UnqueueMessageJob < Postal::Job
       nil
     end
   end
+  # rubocop:enable Layout/LineLength
 
   private
 

app/models/server.rb

@@ -220,6 +220,10 @@ class Server < ApplicationRecord
     }
   end
 
+  # Return the domain which can be used to authenticate emails sent from the given e-mail address.
+  #
+  # @param address [String] an e-mail address
+  # @return [Domain, nil] the domain to use for authentication
   def authenticated_domain_for_address(address)
     return nil if address.blank?
 
@@ -230,14 +234,24 @@ class Server < ApplicationRecord
 
     uname, = uname.split("+", 2)
 
-    # Check the server's domain
-    if domain = Domain.verified.order(owner_type: :desc).where("(owner_type = 'Organization' AND owner_id = ?) OR (owner_type = 'Server' AND owner_id = ?)", organization_id, id).where(name: domain_name).first
-      return domain
-    end
+    # Find a verified domain which directly matches the domain name for the given address.
+    domain = Domain.verified
+                   .order(owner_type: :desc)
+                   .where("(owner_type = 'Organization' AND owner_id = ?) OR " \
+                          "(owner_type = 'Server' AND owner_id = ?)", organization_id, id)
+                   .where(name: domain_name)
+                   .first
 
-    return unless any_domain = domains.verified.where(use_for_any: true).order(:name).first
+    # If there is a matching domain, return it
+    return domain if domain
 
-    any_domain
+    # Otherwise, we need to look to see if there is a domain configured which can be used as the authenticated
+    # domain for any domain. This will look for domains directly within the server and return that.
+    any_domain = domains.verified.where(use_for_any: true).order(:name).first
+    return any_domain if any_domain
+
+    # Return nil if we can't find anything suitable
+    nil
   end
 
   def find_authenticated_domain_from_headers(headers)