Codeigniter emails not reaching Outlook and landing in spam folder in Gmail

I've been working on this code to send emails to people who want to make appointments at a Law Firm. My problem is that my emails don't land anywhere in Outlook and land in the spam folder in Gmail.

I found many suggestions to similar problems online : encrypting the message, using newline("\r\n"), use set_header(), etc. but none of them seem to work. I'm using ovhcloud hosting and CodeIgniter 3.

Here's my controller function, please help :

public function nouveau_rdv(){

    $prenom = $_POST['prenom'];
    $nom = $_POST['nom'];
    $email = $_POST['email'];
    $var = $_POST['date'];
    $date = str_replace('/', '-', $var);
    $date = date('Y-m-d', strtotime($date));
    $sexe = $_POST['sexe'];
    $motif = $_POST['motif'];
    $tel = $_POST['tel'];

if(is_null($email)!=1 && is_null($nom)!=1 && is_null($prenom)!=1 && is_null($motif)!=1 && is_null($date)!=1 && is_null($tel)!=1 && is_null($sexe)!=1)
    {
            $data['prenom'] = $prenom;
            $data['code'] = $this->db_model->nouveau_rdv($nom,$prenom,$email,$sexe,$tel,$date,$motif);

            $config = array(
                'protocol' => 'smtp',
                'smtp_host' => 'smtp.mail.ovh.ca', 
                'smtp_port' => 465,
                'smtp_user' => 'contact@kbhlawfirm.com',
                'smtp_pass' => '********',
                'smtp_crypto' => 'ssl',
                'mailtype' => 'html',
                'smtp_timeout' => '60', 
                'charset' => 'utf-8',
                'newline' => "\r\n",
                'wordwrap' => TRUE,
                'priority' => 1,
                'validation' => TRUE,
                'useragent' => 'CodeIgniter'
            );

            $this->load->library('email',$config);
            $this->email->initialize($config);
            
            $from = 'contact@kbhlawfirm.com';
            $name = 'KBH LAW FIRM';
            $to = $email;
            $subject = "Prise de rendez-vous";
            $message = $this->load->view('email/Bienvenue.php',$data,TRUE);

            $this->email->set_crlf( "\r\n" );
            $this->email->set_newline("\r\n");
            $this->email->from($from, $name);
            $this->email->to($to,$from);
            $this->email->subject($subject);
            $this->email->message($message);
            $this->email->set_header('From ', $from.' <'.$from.'>');

            $this->load->library('encryption');

            if ($this->email->send()) {
                header("location:../success");
            } else {
                show_error($this->email->print_debugger());
            }
                

        }
    else
    {
        header("location:../error");
    }
                
}

source https://stackoverflow.com/questions/67781303/codeigniter-emails-not-reaching-outlook-and-landing-in-spam-folder-in-gmail