PHP send MIME mail with attachment

Reference:
http://www.dk101.com/index.php/viewnews-837.html
http://www.codewalkers.com/c/a/Email-Code/PHP-Email-Attachment-v1/

設定 PHP 寄信：(Linux)
如果有啟用 sendmail 並設定完成，則不需修改 /etc/php.ini。

如果沒有啟用 sendmail，編輯 /etc/php.ini，設定 SMTP = your_mail_server。



寄有附件的 mail：
function mail_with_attach($to, $subject, $message, $filepath, $filename) {
$fileatt = $filepath . '/' . $filename; // Path to the file
$fileatt_type = "application/octet-stream"; // File Type
$fileatt_name = $filename; // Filename that will be used for the file as the attachment

$email_from = "from@domain.com"; // Who the email is from
$email_subject = $subject; // The Subject of the email
$email_txt = $message; // Message that the email has in it

$email_to = $to; // Who the email is to

$headers = "From: ".$email_from;

$file = fopen($fileatt,'rb');
$data = fread($file,filesize($fileatt));
fclose($file);

$semi_rand = md5(time());
$mime_boundary = "==Multipart_Boundary_x{$semi_rand}x";

$headers .= "\nMIME-Version: 1.0\n" .
"Content-Type: multipart/mixed;\n" .
" boundary=\"{$mime_boundary}\"";

$email_message = "This is a multi-part message in MIME format.\n\n" .
"--{$mime_boundary}\n" .
"Content-Type:text/html; charset=\"big5\"\n" .
"Content-Transfer-Encoding: quoted-printable\n\n" .
$email_txt . "\n\n";

$data = chunk_split(base64_encode($data));

$email_message .= "--{$mime_boundary}\n" .
"Content-Type: {$fileatt_type};\n" .
" name=\"{$fileatt_name}\"\n" .
"Content-Transfer-Encoding: base64\n\n" .
$data . "\n\n" .
"--{$mime_boundary}--\n";

$ok = @mail($email_to, $email_subject, $email_message, $headers);

if($ok) {
echo "<font face=verdana size=2>The file was successfully sent!</font>";
} else {
die("Sorry but the email could not be sent. Please go back and try again!");
}
}