Not sending email via Unisender

box https://exampleos.1box.link/ https://exampleos.1box.link/app/unisender/settings/ The integration with Unisender is set up and in the integration it shows that the letters were sent [file]14502[/file] . In fact, the letter did not come to the mail, and also in the service itself it is not visible that letters were sent there [file]14503[/file] . But transferring contacts works correctly [file]14504[/file] . Is it possible to check why the letters were not sent? Perhaps unisender sent some kind of response to the request? But this is not in the logs.