Mail sending time out
Sometimes, Gandi (my mail provider) times out. That case should be handled!
[2019-11-26 10:50:43] prod.ERROR: Swift_TransportException: Connection could not be established with host mail.gandi.net [Connection timed out #110] in /var/www/secretsanta.fr/w ww/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/StreamBuffer.php:277