If you need a solution for multiple attachments in PHP using mail() function take a look below. Code below allows to attach and send 2 files. If you still having problems just take a look at raw email file. Each attachment needs to be divided by mime boundary (same boundary for each file) and this boundary needs to be added at the end of our message.

$logo = $_FILES['logo']['tmp_name'];
$logo_type = $_FILES['logo']['type'];
$logo_name = $_FILES['logo']['name'];
$image      = $_FILES['image']['tmp_name'];
$image_type = $_FILES['image']['type'];
$image_name = $_FILES['image']['name'];

headers = "From: no-reply@mydomainhere.co.uk";
if (is_uploaded_file($logo)) {
$file = fopen($logo,'rb');
$data = fread($file,filesize($logo));
fclose($file);

// Generate a boundary string
$semi_rand = md5(time());
$mime_boundary = "{$semi_rand}";
$rand_id = md5($semi_rand);

// Add the headers for a file attachment
$headers .= "nMIME-Version: 1.0n" .
"Content-Type: multipart/mixed;n" .
" boundary="{$mime_boundary}"";

// Add a multipart boundary above the plain message
$message = "--{$mime_boundary}n" .
"Content-Type: text/plain; charset="iso-8859-1"n" .
"Content-Transfer-Encoding: 7bitnn" .
"Name : $_POST[name] nn" .
"Address : $_POST[address] nn" .
"Description: $_POST[description] nn";

// Base64 encode the file data
$data = chunk_split(base64_encode($data));

// Add file attachment to the message
$message .= "--{$mime_boundary}n" .
"Content-Type: {$logo_type}; name="{$logo_name}"n" .
"Content-Disposition: attachment; filename="{$logo_name}"n" .
"Content-Transfer-Encoding: base64n" .
"X-Attachment-Id: file_{$rand_id}nn" .
$data . "nn";
}

// Second attachment
if (is_uploaded_file($image)) {
// Read the file to be attached ('rb' = read binary)
$file = fopen($image,'rb');
$data = fread($file,filesize($image));
fclose($file);

// Base64 encode the file data
$data = chunk_split(base64_encode($data));

// Add file attachment to the message
$message .= "--{$mime_boundary}n" .
"Content-Type: {$image_type}; name="{$image_name}"n" .
"Content-Disposition: attachment; filename="{$image_name}"n" .
"Content-Transfer-Encoding: base64n" .
"X-Attachment-Id: file_{$rand_id}nn" .
$data . "nn" .
"--{$mime_boundary}--n";
}

// Send the message
$ok = @mail("confirmations@whatever.com", $subject, $message, $headers);
if ($ok) {
echo "OK!";
} else {
echo "Error!!";
}
}

If you need a solution for multiple attachments in PHP using mail() function take a look below. Code below allows to attach and send 2 files. If you still having problems just take a look at raw email file. Each attachment needs to be divided by mime boundary (same boundary for each file) and this boundary needs to be added at the end of our message.