@Vincent-TP I'm not sure if my setup is different - but my SMTP service (brevo) is blocking the email from being sent due to the "from" address being the same as the SMTP server.  I've attached a sensored screenshot of my settings - note my "from" email is *not* the same as my SMTP server username.

And because I don't own the SMTP server username domain, it gets rejected.  I've attached my anonymised config, as well as the error message reported from brevo:

Sending has been rejected because the sender you used xxxxxxx is not valid. Validate your sender or authenticate your domain