[12.x] Allow configuration of retry period for RoundRobin and Failover mail transports

config/mail.php

@@ -85,6 +85,7 @@
                 'smtp',
                 'log',
             ],
+            'retry_after' => 60,
         ],
 
         'roundrobin' => [
@@ -93,6 +94,7 @@
                 'ses',
                 'postmark',
             ],
+            'retry_after' => 60,
         ],
 
     ],

src/Illuminate/Mail/MailManager.php

@@ -385,24 +385,7 @@ protected function createPostmarkTransport(array $config)
      */
     protected function createFailoverTransport(array $config)
     {
-        $transports = [];
-
-        foreach ($config['mailers'] as $name) {
-            $config = $this->getConfig($name);
-
-            if (is_null($config)) {
-                throw new InvalidArgumentException("Mailer [{$name}] is not defined.");
-            }
-
-            // Now, we will check if the "driver" key exists and if it does we will set
-            // the transport configuration parameter in order to offer compatibility
-            // with any Laravel <= 6.x application style mail configuration files.
-            $transports[] = $this->app['config']['mail.driver']
-                ? $this->createSymfonyTransport(array_merge($config, ['transport' => $name]))
-                : $this->createSymfonyTransport($config);
-        }
-
-        return new FailoverTransport($transports);
+        return $this->createRoundrobinTransportOfClass($config, FailoverTransport::class);
     }
 
     /**
@@ -412,6 +395,20 @@ protected function createFailoverTransport(array $config)
      * @return \Symfony\Component\Mailer\Transport\RoundRobinTransport
      */
     protected function createRoundrobinTransport(array $config)
+    {
+        return $this->createRoundrobinTransportOfClass($config, RoundRobinTransport::class);
+    }
+
+    /**
+     * Create an instance of supplied class extending the Symfony Roundrobin Transport driver.
+     *
+     * @template TClass of \Symfony\Component\Mailer\Transport\RoundRobinTransport
+     *
+     * @param  array  $config
+     * @param  class-string<TClass>  $class
+     * @return TClass
+     */
+    protected function createRoundrobinTransportOfClass(array $config, string $class)
     {
         $transports = [];
 
@@ -430,7 +427,7 @@ protected function createRoundrobinTransport(array $config)
                 : $this->createSymfonyTransport($config);
         }
 
-        return new RoundRobinTransport($transports);
+        return new $class($transports, $config['retry_after'] ?? 60);
     }
 
     /**

tests/Mail/MailRoundRobinTransportTest.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace Illuminate\Tests\Mail;
+
+use Orchestra\Testbench\TestCase;
+use Symfony\Component\Mailer\Transport\RoundRobinTransport;
+
+class MailRoundRobinTransportTest extends TestCase
+{
+    public function testGetRoundRobinTransportWithConfiguredTransports()
+    {
+        $this->app['config']->set('mail.default', 'roundrobin');
+
+        $this->app['config']->set('mail.mailers', [
+            'roundrobin' => [
+                'transport' => 'roundrobin',
+                'mailers' => [
+                    'sendmail',
+                    'array',
+                ],
+            ],
+
+            'sendmail' => [
+                'transport' => 'sendmail',
+                'path' => '/usr/sbin/sendmail -bs',
+            ],
+
+            'array' => [
+                'transport' => 'array',
+            ],
+        ]);
+
+        $transport = app('mailer')->getSymfonyTransport();
+        $this->assertInstanceOf(RoundRobinTransport::class, $transport);
+    }
+
+    public function testGetRoundRobinTransportWithLaravel6StyleMailConfiguration()
+    {
+        $this->app['config']->set('mail.driver', 'roundrobin');
+
+        $this->app['config']->set('mail.mailers', [
+            'sendmail',
+            'array',
+        ]);
+
+        $this->app['config']->set('mail.sendmail', '/usr/sbin/sendmail -bs');
+
+        $transport = app('mailer')->getSymfonyTransport();
+        $this->assertInstanceOf(RoundRobinTransport::class, $transport);
+    }
+}