Error when sending preview email with french translation

Hi,

On the settings page, it’s OK to send a preview email. But after I upload the subscribe2-fr_FR.mo I have the following error on the page /wp-admin/admin.php?page=s2_settings&tab=templates when sending the email.

phpmailerException thrown
Invalid address: Pour =?UTF-8?Q?g=C3=A9rer=20les=20options=20de=20votre=20inscription=20?=

Best regards.