[ 'groups' => 'single', ], 'mailgun' => [ 'domain' => env('MAILGUN_DOMAIN'), 'secret' => env('MAILGUN_SECRET'), 'endpoint' => env('MAILGUN_ENDPOINT', 'api.mailgun.net'), ], 'postmark' => [ 'token' => env('POSTMARK_TOKEN'), ], 'ses' => [ 'key' => env('AWS_ACCESS_KEY_ID'), 'secret' => env('AWS_SECRET_ACCESS_KEY'), 'region' => env('AWS_DEFAULT_REGION', 'us-east-1'), ], ];