PHP mail() Outlook-formatering

$headers = "From: $fromEmail"; 
            $headers .= "\nMIME-Version: 1.0\n"; 
            $headers .= "Content-Type: multipart/mixed;\n" ;
            $headers .= " boundary=\"{$mimeBoundary}\"";
            
            $subject = "=?utf-8?B?".base64_encode('Mail från hemsidan')."?=";
            $fromMessage = "This is a multi-part message in MIME format.\n\n" . 
                "--{$mimeBoundary}\n" . 
                "Content-Type: text/plain; charset=\"UTF-8\"\n" . 
                "Content-Transfer-Encoding: 7bit\n\n" . 
                "Namn: " . $fromName . "\nTelefon: " . $fromPhone . "\nEmail: " . $fromEmail . "\n\n" . $fromMessage . "\n\n";
            
                
                    foreach($_FILES as $files){
                        $tmp_name = $files['tmp_name'];
                        $type = $files['type'];
                        $name = $files['name'];
                        $size = $files['size'];
                        if(file_exists($tmp_name)){
                            if(is_uploaded_file($tmp_name)){
                                $file = fopen($tmp_name, 'rb');
                                $data = fread($file, filesize($tmp_name));
                                fclose($file);
                                $data = chunk_split(base64_encode($data));
                            }
                            $fromMessage .= "--{$mime_boundary}\n" .
                            "Content-Type: {$type};\n" .
                            " name=\"{$name}\"\n" .
                            "Content-Disposition: attachment;\n" .
                            " filename=\"{$fileatt_name}\"\n" .
                            "Content-Transfer-Encoding: base64\n\n" .
                            $data . "\n\n";
                        }
                        
                    }
                $fromMessage.="--{$mime_boundary}--\n";

This is a multi-part message in MIME format.

--
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit

Namn: Robin
Telefon: 0701234567
Email: some@mail.com

test 3

--==Multipart_Boundary_x494bf91406f7ad34a9df4d534b2cd8e6x
Content-Type: image/jpeg;
 name="6_2.jpg"
Content-Disposition: attachment;
 filename=""
Content-Transfer-Encoding: base64

/9j/4RR3RXhpZgAATU0AKgAAAAgABwESAAMAAAABAAEAAAEaAAUAAAABAAAAYgEbAAUAAAABAAAA
agEoAAM(....   ....)L/B/uxp3+f8AqX/Qg1P/AJcX/lma/ev/AMdjP++cRpX/APXHo3/vaf8A2f/Z


--==Multipart_Boundary_x494bf91406f7ad34a9df4d534b2cd8e6x--