Although I have no personal knowledge of that server configuration, if you would please post a screenshot if the SMTP server settings pane, someone here may have the needed information you seek. Thank you.

''<p>Marie BORDET [[#question-1518534|said]]</p>'' <blockquote>Good evening, for several months now I have been unable to send emails with Thunderbird. Orange assures me that the SMTP server is working. Thank you for your help. Marie Bordet </blockquote> Are you using the recommended settings, as well as a separate password for 3rd-party apps like TB? imap.orange.fr, 993, SSL/TLS, normal password, email address smtp.orange.fr, 465, SSL/TLS, normal password, email address https://assistance.orange.fr/ordinateurs-peripheriques/installer-et-utiliser/l-utilisation-du-mail-et-du-cloud/mail-orange/le-mail-orange-nouvelle-version/parametrer-la-boite-mail/mail-orange-comment-acceder-a-sa-boite-mail-orange-depuis-une-application-ou-un-logiciel-de-messagerie-non-fourni-par-orange_434630-964290#