类Swift\u Transport\u Esmtp\u Auth\u cramd5authenticator不存在

在config/mail.php中设置了正确的配置之后，我似乎无法发送启用了laravel 5.4的电子邮件。我正在使用smtp驱动程序，这里是我的文件摘要。
下面是配置/mail.php

<?php
return [
    'driver'=>env('MAIL_DRIVER', 'smtp'),       
    'host'=>env('MAIL_HOST', 'smtp.gmail.com'),
'port' => env('MAIL_PORT', 587),
'from' => [
    'address' => env('MAIL_FROM_ADDRESS', 'info@afecamworld.org'),
    'name' => env('MAIL_FROM_NAME', 'National President'),
],
'encryption' => env('MAIL_ENCRYPTION', 'ssl'),
'username' => env('MAIL_USERNAME', 'my-gmail-email'),
'password' => env('MAIL_PASSWORD', 'my-gmail-password'),
'sendmail' => '/usr/sbin/sendmail -bs',
'markdown' => [
    'theme' => 'default',
    'paths' => [
        resource_path('views/vendor/mail'),
    ],
],              

类Swift\u Transport\u Esmtp\u Auth\u cramd5authenticator不存在 在DependencyContainer.php中（第309行）

<?php
return [
    'driver'=>env('MAIL_DRIVER', 'smtp'),       
    'host'=>env('MAIL_HOST', 'smtp.gmail.com'),
'port' => env('MAIL_PORT', 587),
'from' => [
    'address' => env('MAIL_FROM_ADDRESS', 'info@afecamworld.org'),
    'name' => env('MAIL_FROM_NAME', 'National President'),
],
'encryption' => env('MAIL_ENCRYPTION', 'ssl'),
'username' => env('MAIL_USERNAME', 'my-gmail-email'),
'password' => env('MAIL_PASSWORD', 'my-gmail-password'),
'sendmail' => '/usr/sbin/sendmail -bs',
'markdown' => [
    'theme' => 'default',
    'paths' => [
        resource_path('views/vendor/mail'),
    ],
],              

---

如果您能帮助我在dreamhost上解决此错误，我将不胜感激，谢谢。

解决此问题的最佳方法是删除供应商文件夹中的文件，然后重做composer安装和composer更新，这就是我解决问题的方法。

我需要尽快获得帮助，谢谢。

<?php
return [
    'driver'=>env('MAIL_DRIVER', 'smtp'),       
    'host'=>env('MAIL_HOST', 'smtp.gmail.com'),
'port' => env('MAIL_PORT', 587),
'from' => [
    'address' => env('MAIL_FROM_ADDRESS', 'info@afecamworld.org'),
    'name' => env('MAIL_FROM_NAME', 'National President'),
],
'encryption' => env('MAIL_ENCRYPTION', 'ssl'),
'username' => env('MAIL_USERNAME', 'my-gmail-email'),
'password' => env('MAIL_PASSWORD', 'my-gmail-password'),
'sendmail' => '/usr/sbin/sendmail -bs',
'markdown' => [
    'theme' => 'default',
    'paths' => [
        resource_path('views/vendor/mail'),
    ],
],