Map connection_time_limit to ping_threshold.

config/vufind/config.ini

@@ -704,6 +704,14 @@ port            = 25
 ; connection. If no explicit protocol ('tls' or 'ssl') is configured, a protocol
 ; based on the configured port is chosen (587 -> tls, 487 -> ssl).
 ;secure         = tls
+; This setting enforces a limit (in seconds) on the lifetime of an SMTP
+; connection before the connection is checked, which can be useful when sending
+; batches of emails, since it can help avoid errors caused by server timeouts.
+; This is mapped to the ping_threshold option in Symfony Mailer.
+; Comment out the setting to use the default ping threshold.
+; See https://symfony.com/doc/current/mailer.html#other-options for more
+; information.
+connection_time_limit = 60
 ; The server name to report to the upstream mail server when sending mail.
 ;name = vufind.myuniversity.edu
 

module/VuFind/src/VuFind/Mailer/Factory.php

@@ -85,8 +85,16 @@ protected function getDSN(array $config): string
         if ($port = $config['Mail']['port'] ?? null) {
             $dsn .= ":$port";
         }
+
+        $dsnParams = [];
         if ($name = $config['Mail']['name'] ?? null) {
-            $dsn .= "?local_domain=$name";
+            $dsnParams['local_domain'] = $name;
+        }
+        if (null !== ($limit = $config['Mail']['connection_time_limit'] ?? null)) {
+            $dsnParams['ping_threshold'] = $limit;
+        }
+        if ($dsnParams) {
+            $dsn .= '?' . http_build_query($dsnParams);
         }
 
         return $dsn;

module/VuFind/tests/unit-tests/src/VuFindTest/Mailer/MailerTest.php

@@ -62,9 +62,10 @@ public function testFactoryConfiguration()
             'Mail' => [
                 'host' => 'vufindtest.localhost',
                 'port' => 123,
-                'name' => 'foo',
+                'name' => 'foo?bar',
                 'username' => 'vufinduser',
                 'password' => 'vufindpass',
+                'connection_time_limit' => 60,
             ],
         ];
         $configDsn = [
@@ -78,7 +79,7 @@ public function testFactoryConfiguration()
         $factory = new MailerFactory();
 
         $this->assertEquals(
-            'smtp://vufinduser:[email protected]:123?local_domain=foo',
+            'smtp://vufinduser:[email protected]:123?local_domain=foo%3Fbar&ping_threshold=60',
             $this->callMethod($factory, 'getDSN', [$config])
         );