Merge branch 'master' of github.com:beyondcode/laravel-mailbox

Author: mpociot

src/InboundEmail.php

@@ -128,6 +128,12 @@ public function message(): MimeMessage
 
     public function reply(Mailable $mailable)
     {
+        if ($mailable instanceof \Illuminate\Mail\Mailable) {
+            $mailable->withSwiftMessage(function (\Swift_Message $message) {
+                $message->getHeaders()->addIdHeader('In-Reply-To', $this->id());
+            });
+        }
+
         return Mail::to($this->from())->send($mailable);
     }
 

tests/InboundEmailTest.php

@@ -113,7 +113,6 @@ public function it_stores_inbound_emails_with_fallback_and_catchall_only_once()
         $this->assertSame(2, InboundEmail::query()->count());
     }
 
-
     /** @test */
     public function it_does_not_store_inbound_emails_if_configured()
     {