发送邮件失败

( ! ) Fatal error: Uncaught exception 'Swift_TransportException' with message ' in D:\phpcode\www\muke\demo\pdo\app\swiftmailer-master\lib\classes\Swift\Transport\StreamBuffer.php on line271

( ! ) Swift_TransportException: in D:\phpcode\www\muke\demo\pdo\app\swiftmailer-master\lib\classes\Swift\Transport\StreamBuffer.php on line 271

app\swiftmailer-master\lib\classes\Swift\Transport\StreamBuffer.php

源码这个里面没得Swift_TransportException函数。咋弄？？自己随便建一个？