Yes that’s exactly it.
In fact, regular WordPress emails are not sent.
But when I turn off:
WooCommerce – MailerLite or WooCommerce Subscribe to the Sendinblue newsletter
The regular emails and contact form work again.
Knowing that before the update I had these plugins and send them emails were working.
I tested in a PHP file the wp_mail function of wordpress returns false when I have these plugins activated, but the php mail function works (so I eliminate the server as the source of the problem)`