ldc-legaulois/app/Mail/ContactComplainMail.php

<?php

namespace App\Mail;

class ContactComplainMail extends ContactMail
{
    /**
     * Build the message.
     *
     * @return $this
     */
    public function build()
    {
        return $this->view('emails.contact-passerelle')
            ->subject(sprintf('Nouveau message consommateur Le Gaulois (%s)', $this->data->type->label()))
            ->text('emails.contact-passerelle-plain')
            ->with('data', $this->data)
            ->attachData(
                view('emails.passerelle-xml', ['data' => $this->data->exportToPasserelleDataArray()])->render(),
                sprintf('LEGAULOIS_PASS_MESSAGE_%d.xml', date('YmdHis')),
                ['mime' => 'application/xml']
            );
    }
}