详情描述：新用户注册后提示错误（管理员检查前台名录已注册成功）
报错内容：开启Dbug后错误信息如下：
POST https://wedog.cc/register
Swift_TransportException: Expected response code 354 but got code "503", with message "503 bad sequence of commands
" in file /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php on line 457
Stack trace:
1. Swift_TransportException->() /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:457
2. Swift_Transport_AbstractSmtpTransport->assertResponseCode() /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:341
3. Swift_Transport_AbstractSmtpTransport->executeCommand() /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/EsmtpTransport.php:305
4. Swift_Transport_EsmtpTransport->executeCommand() /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:390
5. Swift_Transport_AbstractSmtpTransport->doDataCommand() /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:497
6. Swift_Transport_AbstractSmtpTransport->doMailTransaction() /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:516
7. Swift_Transport_AbstractSmtpTransport->sendTo() /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:206
8. Swift_Transport_AbstractSmtpTransport->send() /www/wwwroot/www.wedog.cc/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Mailer.php:71
9. Swift_Mailer->send() /www/wwwroot/www.wedog.cc/vendor/illuminate/mail/Mailer.php:483
10. Illuminate\Mail\Mailer->sendSwiftMessage() /www/wwwroot/www.wedog.cc/vendor/illuminate/mail/Mailer.php:259
11. Illuminate\Mail\Mailer->send() /www/wwwroot/www.wedog.cc/vendor/illuminate/mail/Mailer.php:171
12. Illuminate\Mail\Mailer->html() /www/wwwroot/www.wedog.cc/vendor/fof/pretty-mail/src/Mailer.php:55
13. FoF\PrettyMail\Mailer->raw() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Mail/Job/SendRawEmailJob.php:34
14. Flarum\Mail\Job\SendRawEmailJob->handle() /www/wwwroot/www.wedog.cc/vendor/illuminate/container/BoundMethod.php:29
15. call_user_func_array() /www/wwwroot/www.wedog.cc/vendor/illuminate/container/BoundMethod.php:29
16. Illuminate\Container\BoundMethod->Illuminate\Container\{closure}() /www/wwwroot/www.wedog.cc/vendor/illuminate/container/BoundMethod.php:87
17. Illuminate\Container\BoundMethod->callBoundMethod() /www/wwwroot/www.wedog.cc/vendor/illuminate/container/BoundMethod.php:31
18. Illuminate\Container\BoundMethod->call() /www/wwwroot/www.wedog.cc/vendor/illuminate/container/Container.php:572
19. Illuminate\Container\Container->call() /www/wwwroot/www.wedog.cc/vendor/illuminate/bus/Dispatcher.php:94
20. Illuminate\Bus\Dispatcher->Illuminate\Bus\{closure}() /www/wwwroot/www.wedog.cc/vendor/illuminate/pipeline/Pipeline.php:128
21. Illuminate\Pipeline\Pipeline->Illuminate\Pipeline\{closure}() /www/wwwroot/www.wedog.cc/vendor/illuminate/pipeline/Pipeline.php:104
22. Illuminate\Pipeline\Pipeline->then() /www/wwwroot/www.wedog.cc/vendor/illuminate/bus/Dispatcher.php:98
23. Illuminate\Bus\Dispatcher->dispatchNow() /www/wwwroot/www.wedog.cc/vendor/illuminate/queue/CallQueuedHandler.php:49
24. Illuminate\Queue\CallQueuedHandler->call() /www/wwwroot/www.wedog.cc/vendor/illuminate/queue/Jobs/Job.php:83
25. Illuminate\Queue\Jobs\Job->fire() /www/wwwroot/www.wedog.cc/vendor/illuminate/queue/SyncQueue.php:42
26. Illuminate\Queue\SyncQueue->push() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/User/AccountActivationMailer.php:68
27. Flarum\User\AccountActivationMailer->handle() /www/wwwroot/www.wedog.cc/vendor/illuminate/events/Dispatcher.php:379
28. call_user_func_array() /www/wwwroot/www.wedog.cc/vendor/illuminate/events/Dispatcher.php:379
29. Illuminate\Events\Dispatcher->Illuminate\Events\{closure}() /www/wwwroot/www.wedog.cc/vendor/illuminate/events/Dispatcher.php:209
30. Illuminate\Events\Dispatcher->dispatch() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Foundation/DispatchEventsTrait.php:33
31. Flarum\User\Command\RegisterUserHandler->dispatchEventsFor() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/User/Command/RegisterUserHandler.php:114
32. Flarum\User\Command\RegisterUserHandler->handle() /www/wwwroot/www.wedog.cc/vendor/illuminate/bus/Dispatcher.php:90
33. Illuminate\Bus\Dispatcher->Illuminate\Bus\{closure}() /www/wwwroot/www.wedog.cc/vendor/illuminate/pipeline/Pipeline.php:128
34. Illuminate\Pipeline\Pipeline->Illuminate\Pipeline\{closure}() /www/wwwroot/www.wedog.cc/vendor/illuminate/pipeline/Pipeline.php:104
35. Illuminate\Pipeline\Pipeline->then() /www/wwwroot/www.wedog.cc/vendor/illuminate/bus/Dispatcher.php:98
36. Illuminate\Bus\Dispatcher->dispatchNow() /www/wwwroot/www.wedog.cc/vendor/illuminate/bus/Dispatcher.php:76
37. Illuminate\Bus\Dispatcher->dispatch() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Api/Controller/CreateUserController.php:45
38. Flarum\Api\Controller\CreateUserController->data() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Api/Controller/AbstractSerializeController.php:96
39. Flarum\Api\Controller\AbstractSerializeController->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Api/Controller/AbstractCreateController.php:22
40. Flarum\Api\Controller\AbstractCreateController->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Api/Client.php:72
41. Flarum\Api\Client->send() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Forum/Controller/RegisterController.php:58
42. Flarum\Forum\Controller\RegisterController->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/RouteHandlerFactory.php:38
43. Flarum\Http\RouteHandlerFactory->Flarum\Http\{closure}() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/DispatchRoute.php:65
44. Flarum\Http\Middleware\DispatchRoute->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
45. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/fof/terms/src/Middlewares/RegisterMiddleware.php:54
46. FoF\Terms\Middlewares\RegisterMiddleware->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
47. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/ShareErrorsFromSession.php:57
48. Flarum\Http\Middleware\ShareErrorsFromSession->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
49. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/SetLocale.php:50
50. Flarum\Http\Middleware\SetLocale->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
51. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/CheckCsrfToken.php:45
52. Flarum\Http\Middleware\CheckCsrfToken->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
53. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/AuthenticateWithSession.php:32
54. Flarum\Http\Middleware\AuthenticateWithSession->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
55. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/RememberFromCookie.php:51
56. Flarum\Http\Middleware\RememberFromCookie->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
57. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/StartSession.php:61
58. Flarum\Http\Middleware\StartSession->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
59. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/CollectGarbage.php:46
60. Flarum\Http\Middleware\CollectGarbage->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
61. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/ParseJsonBody.php:28
62. Flarum\Http\Middleware\ParseJsonBody->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
63. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Middleware/HandleErrors.php:57
64. Flarum\Http\Middleware\HandleErrors->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
65. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php:84
66. Laminas\Stratigility\MiddlewarePipe->process() /www/wwwroot/www.wedog.cc/vendor/middlewares/request-handler/src/RequestHandler.php:84
67. Middlewares\RequestHandler->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
68. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/middlewares/base-path-router/src/BasePathRouter.php:97
69. Middlewares\BasePathRouter->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
70. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Middleware/OriginalMessages.php:42
71. Laminas\Stratigility\Middleware\OriginalMessages->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
72. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/middlewares/base-path/src/BasePath.php:53
73. Middlewares\BasePath->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/Next.php:61
74. Laminas\Stratigility\Next->handle() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php:84
75. Laminas\Stratigility\MiddlewarePipe->process() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php:73
76. Laminas\Stratigility\MiddlewarePipe->handle() /www/wwwroot/www.wedog.cc/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php:96
77. Laminas\HttpHandlerRunner\RequestHandlerRunner->run() /www/wwwroot/www.wedog.cc/vendor/flarum/core/src/Http/Server.php:42
78. Flarum\Http\Server->listen() /www/wwwroot/www.wedog.cc/public/index.php:26
已尝试的解决办法：怀疑是不是swiftmailer/swiftmailer整个插件导致的，后台检查没有发现整个插件的开关，有可能是依赖插件，尚无头绪。