How to get the url of different forms and validate via javascript

I am currently doing so and every time I submit the form the alert returns error even with the fields filled in correctly

$('.form-ajax').on('submit', function(e) {
        e.preventDefault();

        var form = $('#formnews');

        $.ajax({
            method: 'POST',
            url: form.attr('action'),
            async: true,
            data: form.serialize(),
            cache: false,
            success: function(result) {
                if (result.success) {
                    swal('Bom trabalho!', 'Sua inscrição foi efetuada com sucesso!', 'success');
                    $('#formnews').val('');
                } else {
                    swal('Alguma coisa errada', result.message, 'warning');
                }
            },
            error: function(data) {
                swal('Erro!', 'Ocorreu um erro', 'error');
            }
        })
    });

<form action="{{ route('newsletter.post.ajax') }}" method="POST" id="formnews">
                    {{ csrf_field() }}
                    <div class="field has-addons">
                        <div class="control is-expanded has-icons-left has-icons-right">
                            <div class="form-group{{ $errors->has('email') ? ' has-error' : '' }}">
                                <p class="control is-expanded has-icons-left has-icons-right">
                                    <input id="email_newsletter" type="email_newsletter" class="input" name="email_newsletter" value="{{ old('email_newsletter') }}" placeholder="Seu melhor email" required>
                                        @if ($errors->has('email'))
                                            <span class="help-block">
                                                <strong>{{ $errors->first('email') }}</strong>
                                            </span>
                                        @endif
                                    <span class="icon is-small is-left">
                                            <i class="fa fa-envelope"></i>
                                    </span>
                                    <span class="icon is-small is-right">
                                             <i class="fa fa-check"></i>
                                    </span>
                                </p>
                            </div>
                        </div>
                        <div class="control">
                            <button type="submit" class="button is-warning">
                                Cadastrar
                            </button>
                        </div>
                    </div>
               </form>