Question

=======UPDATE========

The problem ended up being that I was using the header ContentType when I should have been using Content-Type.

Thanks for your help guys.

Derp derp derp.

=======/UPDATE=======

I apologize in advance for the obnoxiously long question.

I’m attempting to send emails with attachments through PHP. I’ve done this successfully before with a single attachment. But I can’t get it to work with multiple attachments, or for that matter now with a single attachment using this method. So, what am I doing wrong?

I understand that there are other libraries for these functions available. But I want to know WHY this one is not working.

Here is the method that generates the actual email:

function gen_mail ()
{
    $files = $this->files();
    $has_attachments = (bool) $files;

    $EOL = "\r\n"; // tried \n, PHP_EOL
    $message = $this->message;

    $headers = $this->gen_headers();
    $headers .= "MIME-Version: 1.0$EOL";

    if ($has_attachments) {
        $hash = md5(time());
        $sep = "=={$hash}==";
        $headers .= "ContentType: multipart/mixed; boundary=\"$sep\"$EOL$EOL";
        $headers .= "This is a MIME-encoded message.$EOL$EOL";
        $headers .= "--$sep$EOL";
    }

    $headers .= "Content-Type: text/html; charset=\"iso-8859-1\"$EOL";
    $headers .= "Content-Disposition: inline$EOL";
    $headers .= "Content-Transfer-Encoding: 7bit$EOL$EOL";
    $headers .= "$message$EOL$EOL";

    if ($has_attachments) { // here go attachments
        foreach ($files as $key => $value) {
            $filename = is_numeric($key)? basename($value) : $key;
            $file = fopen($value, 'rb');
            $data = fread($file, filesize($value));
                            fclose($file);
            $content = chunk_split(base64_encode($data));
            $headers .= "--$sep$EOL";
            $headers .= "Content-Type: application/octet-stream; ";
            $headers .= "name=\"$filename\"$EOL";
            $headers .= "Content-Transfer-Encoding: base64$EOL";
            // tried Content-Disposition, attachment, and every combination
            $headers .= "Content-Description: inline; $EOL ";
            $headers .= "filename=\"$filename\"$EOL$EOL";
            $headers .= "$content$EOL$EOL";
        }
        $headers .= "--$sep--$EOL$EOL";
    }
    return $headers;
}

And this is what the headers returned by the above function look like:

From: [e-mail]
MIME-Version: 1.0
ContentType: multipart/mixed; boundary="==cd42448edf10bca4640bc7d6365e1961=="

This is a MIME-encoded message.

--==cd42448edf10bca4640bc7d6365e1961==
Content-Type: text/html; charset="iso-8859-1"
Content-Disposition: inline
Content-Transfer-Encoding: 7bit

Travis, you are so cool!!!1!

--==cd42448edf10bca4640bc7d6365e1961==
Content-Type: application/octet-stream; name="html.login.php"
Content-Transfer-Encoding: base64
Content-Description: inline; 
 filename="html.login.php"

PD9waHANCgkNCiRoZWFkZXJfY29uZmlnID0gYXJyYXkoKTsNCiRtc2cgPSAnUmVnaXN0ZXJlZCBP
cGVyYXRvcnMsIGVudGVyIHlvdXIgT3BlcmF0b3IgSUQgYW5kIHBhc3N3b3JkIHRvIGxvZ2luJzsN
CiRtc2dfY2xhc3MgPSAnbm9ybWFsJzsNCmlmICgkbG9nZ2VkX2luKSB7DQoJJGhlYWRlcl9jb25m
aWdbJ2NvbnRyb2xzJ10gPSBhcnJheSAoDQoJCWFycmF5ICgndGV4dCcgPT4gJ1N1Ym1pdCBFbnRy
aWVzJywgJ2hyZWYnID0+ICdlbnRyeScpLA0KCSk7DQoJJG1zZyA9ICdZb3UgYXJlIGxvZ2dlZCBp
bi4gVXNlIHRoZSBhYm92ZSBsaW5rcywgb3IgDQoJCWNsaWNrIDxhIGhyZWY9ImVudHJ5Ij5oZXJl
PC9hPiB0byBiZWdpbiBvciByZXN1bWUgYSBqb2InOw0KCSRtc2dfY2xhc3MgPSAnc3VjY2Vzcyc7
DQp9DQoNCj8+


--==cd42448edf10bca4640bc7d6365e1961==--

I’ve tried functions written by other people, and they produce seemingly identical output. But when I send those headers with
mail($address, $subject, ”, $headers)

I get this in my inbox:

This is a MIME-encoded message.

--==cd42448edf10bca4640bc7d6365e1961==
Content-Type: text/html; charset="iso-8859-1"
Content-Disposition: inline
Content-Transfer-Encoding: 7bit

Travis, you are so cool!!!1!

--==cd42448edf10bca4640bc7d6365e1961==
Content-Type: application/octet-stream; name="html.login.php"
Content-Transfer-Encoding: base64
Content-Description: inline;
 filename="html.login.php"

PD9waHANCgkNCiRoZWFkZXJfY29uZmlnID0gYXJyYXkoKTsNCiRtc2cgPSAnUmVnaXN0ZXJlZCBP
cGVyYXRvcnMsIGVudGVyIHlvdXIgT3BlcmF0b3IgSUQgYW5kIHBhc3N3b3JkIHRvIGxvZ2luJzsN
CiRtc2dfY2xhc3MgPSAnbm9ybWFsJzsNCmlmICgkbG9nZ2VkX2luKSB7DQoJJGhlYWRlcl9jb25m
aWdbJ2NvbnRyb2xzJ10gPSBhcnJheSAoDQoJCWFycmF5ICgndGV4dCcgPT4gJ1N1Ym1pdCBFbnRy
aWVzJywgJ2hyZWYnID0+ICdlbnRyeScpLA0KCSk7DQoJJG1zZyA9ICdZb3UgYXJlIGxvZ2dlZCBp
bi4gVXNlIHRoZSBhYm92ZSBsaW5rcywgb3IgDQoJCWNsaWNrIDxhIGhyZWY9ImVudHJ5Ij5oZXJl
PC9hPiB0byBiZWdpbiBvciByZXN1bWUgYSBqb2InOw0KCSRtc2dfY2xhc3MgPSAnc3VjY2Vzcyc7
DQp9DQoNCj8+


--==cd42448edf10bca4640bc7d6365e1961==--

Answer 1

You’ve got the wrong header. It’s “Content-Disposition”, not “Content-Description”. Try:

Content-Disposition: attachment; filename="html.login.php"

instead. Content-Description is to add a short DESCRIPTION of what the attachment is, e.g. “This is my resume” and has nothing to do at all with telling the mail client how to deal with the attachment.