Send Attachments With PHP Mail()?

To send an email with attachment we need to use the multipart/mixed MIME type that specifies that mixed types will be included in the email. Moreover, we want to use multipart/alternative MIME type to send both plain-text and HTML version of the email.Have a look at the example:

$filename = 'file';
$path = 'your path goes here';
$file = $path . "/" . $filename;

$mailto = 'to@mail.com';
$subject = 'Subject';
$message = 'My message';

$content = file_get_contents($file);
$content = chunk_split(base64_encode($content));

// a random hash will be necessary to send mixed content
$separator = md5(time());

// carriage return type (RFC)
$eol = "\r\n";

// main header (multipart mandatory)
$headers = "From: name <from@mail.com>" . $eol;
$headers .= "MIME-Version: 1.0" . $eol;
$headers .= "Content-Type: multipart/mixed; boundary=\"" . $separator . "\"" . $eol;
$headers .= "Content-Transfer-Encoding: 7bit" . $eol;
$headers .= "This is a MIME encoded message." . $eol;

// message
$body = "--" . $separator . $eol;
$body .= "Content-Type: text/plain; charset=\"iso-8859-1\"" . $eol;
$body .= "Content-Transfer-Encoding: 8bit" . $eol;
$body .= $message . $eol;

// attachment
$body .= "--" . $separator . $eol;
$body .= "Content-Type: application/octet-stream; name=\"" . $filename . "\"" . $eol;
$body .= "Content-Transfer-Encoding: base64" . $eol;
$body .= "Content-Disposition: attachment" . $eol;
$body .= $content . $eol;
$body .= "--" . $separator . "--";

//SEND Mail
if (mail($mailto, $subject, $body, $headers)) {
echo "mail send ... OK"; // or use booleans here
} else {
echo "mail send ... ERROR!";
print_r( error_get_last() );
}