reset password does not work with mailgun configuration

I configured laravel 5.1 according to mail docs. Sending mail works fine.

Next step was to add the reset password according to resetting passwords docs. Here I struggle to send the link to the reset-password formular.

Seems like the function to send the reset mail is not triggered. I checked as well with the config/mail.php configuration pretend = true;. There was no entry in the logfile, that a email was send.

Somehow its as well hard to debug, as I could not find the function where the reset email is triggered.

1. How do I send the reset password with mailgun?
2. Where is the function locate to send the reset password, or where can I overwrite it, to test it?

This are my configurations:

.env

# ...
MAIL_DRIVER=mailgun
MAIL_HOST=smtp.mail.org
MAIL_PORT=587
MAIL_USERNAME=null
MAIL_PASSWORD=null
MAILGUN_DOMAIN=mg.foo.com
MAILGUN_SECRET=key-foobar.etc
# ....

config/service.php

//...
'mailgun' => [
    'domain' => env('MAILGUN_DOMAIN'),
    'secret' => env('MAILGUN_SECRET'),
],
//...

config/mail.php

// ...
'driver' => env('MAIL_DRIVER', 'smtp'),
'host' => env('MAIL_HOST', 'smtp.mailgun.org'),
'port' => env('MAIL_PORT', 587),
'from' => ['address' => 'foo@test.com', 'name' => 'foo'],
'encryption' => env('MAIL_ENCRYPTION', 'tls'),
'username' => env('MAIL_USERNAME'),
'password' => env('MAIL_PASSWORD'),
'pretend' => false,
// ...

app/Http/routes.php

// ...
Route::group([
    'prefix' => LaravelLocalization::setLocale(),
    'middleware' => [ 'localeSessionRedirect', 'localizationRedirect' ]
    ], function() {

    //Route::controllers([ 'password' => 'Auth\PasswordController', ]);

    // works only if the user is logged out!!!1
    // Password reset link request routes...
    Route::get('password/email', 'Auth\PasswordController@getEmail');
    Route::post('password/email', 'Auth\PasswordController@postEmail');

    // Password reset routes...
    Route::get('password/reset/{token}', 'Auth\PasswordController@getReset');
    Route::post('password/reset', 'Auth\PasswordController@postReset');
});
//...

resources/views/auth/password.blade.php

@extends('layout')

@section('content')
<div class="container">
    <form method="POST" action="/password/email">
        {!! csrf_field() !!}

        @if (count($errors) > 0)
            <ul>
                @foreach ($errors->all() as $error)
                    <li></li>
                @endforeach
            </ul>
        @endif
    <div class="row">
        <div class="col-md-6">
            {!! Form::label('email', trans( 'mes.email' )) !!}
            <input type="email" name="email" value="" class="form-control">
        </div>
        <div class="col-md-8">
            <button type="submit" class="btn">
                Send Password Reset Link
            </button>
        </div>
    <div>

    </form>
</div>
@endsection

via Chebli Mohamed