Update mail from (#17)

* feat: Add message token to return path

Adding the message token to the return path would be beneficial for users to link bounces to email addresses when X-Postal-MsgID was not included in the bounce message's headers.

Signed-off-by: jmdunsing <113212353+jmdunsing@users.noreply.github.com>

* test: update smtp_sender_spect.rb to reflect design changes to mail from

Signed-off-by: jmdunsing <113212353+jmdunsing@users.noreply.github.com>

---------

Signed-off-by: jmdunsing <113212353+jmdunsing@users.noreply.github.com>

app/senders/smtp_sender.rb

@@ -142,10 +142,10 @@ def determine_mail_from_for_message(message)
     # If the domain has a valid custom return path configured, return
     # that.
     if message.domain.return_path_status == "OK"
-      return "#{message.server.token}@#{message.domain.return_path_domain}"
+      return "#{message.server.token}+#{message.token}@#{message.domain.return_path_domain}"
     end
 
-    "#{message.server.token}@#{Postal::Config.dns.return_path_domain}"
+    "#{message.server.token}+#{message.token}@#{Postal::Config.dns.return_path_domain}"
   end
 
   # Return the RCPT TO to use for the given message in this sending session

spec/senders/smtp_sender_spec.rb

@@ -261,7 +261,7 @@
             sender.send_message(message)
             expect(sender.endpoints.last).to have_received(:send_message).with(
               kind_of(String),
-              "#{server.token}@#{domain.return_path_domain}",
+              "#{server.token}+#{message.token}@#{domain.return_path_domain}",
               ["john@example.com"]
             )
           end
@@ -272,7 +272,7 @@
             sender.send_message(message)
             expect(sender.endpoints.last).to have_received(:send_message).with(
               kind_of(String),
-              "#{server.token}@#{Postal::Config.dns.return_path_domain}",
+              "#{server.token}+#{message.token}@#{Postal::Config.dns.return_path_domain}",
               ["john@example.com"]
             )
           end
@@ -306,7 +306,7 @@
           it "adds the resent-sender header" do
             sender.send_message(message)
             expect(sender.endpoints.last).to have_received(:send_message).with(
-              "Resent-Sender: #{server.token}@#{Postal::Config.dns.return_path_domain}\r\n#{message.raw_message}",
+              "Resent-Sender: #{server.token}+#{message.token}@#{Postal::Config.dns.return_path_domain}\r\n#{message.raw_message}",
               kind_of(String),
               kind_of(Array)
             )