laradock 部署 larabbs 之后，smtp 如何配置？已经按说明修改过.env、甚至 config/mail.php。

首先尝试配置项目的.env：

MAIL_DRIVER=smtp
MAIL_HOST=smtp.mxhichina.com
MAIL_PORT=25
MAIL_USERNAME=name@domain
MAIL_PASSWORD=SECRET
MAIL_ENCRYPTION=

该配置是按阿里企业邮箱说明做的，larabbs跑起来之后，注册新用户，收不到邮件。

然后，尝试直接写入config/mail.php，没太理解sendmail和markdown：

<?php

return [
    'driver' => env('MAIL_DRIVER', 'smtp'),
    'host' => env('MAIL_HOST', 'smtp.mxhichina.com'),
    'port' => env('MAIL_PORT', 25),
    'from' => [
        'address' => env('MAIL_FROM_ADDRESS', 'name@domain'),
        'name' => env('MAIL_FROM_NAME', 'name@domain'),
    ],
    'encryption' => env('MAIL_ENCRYPTION', ''),
    'username' => env('MAIL_USERNAME', "name@domain"),
    'password' => env('MAIL_PASSWORD', "SECRET"),

    /*
    |--------------------------------------------------------------------------
    | Sendmail System Path
    |--------------------------------------------------------------------------
    |
    | When using the "sendmail" driver to send e-mails, we will need to know
    | the path to where Sendmail lives on this server. A default path has
    | been provided here, which will work well on most of your systems.
    |
    */

    'sendmail' => '/usr/sbin/sendmail -bs',

    /*
    |--------------------------------------------------------------------------
    | Markdown Mail Settings
    |--------------------------------------------------------------------------
    |
    | If you are using Markdown based email rendering, you may configure your
    | theme and component paths here, allowing you to customize the design
    | of the emails. Or, you may simply stick with the Laravel defaults!
    |
    */

    'markdown' => [
        'theme' => 'default',

        'paths' => [
            resource_path('views/vendor/mail'),
        ],
    ],

];

又尝试按A帖配置了sendmail（这里其实有误区——下述）；
发现没有该贴所说的mail命令；
又按B帖安装mail命令，还是没有mail命令。

至此，发现这是误区。。。sendmail是个服务？且不论docker容器中不推荐多个进程，也未见larabbs安装文档中提及任何sendmail配置。

决定停下来求助，免得在错误的道路上浪费时间。