php邮件在某些服务器上发送空白内容

I created a class to simplify the use of mail() (with the possibility to add attachments, switch between text and html mode etc).

I'm currently facing this problem :

• When I try to send a mail from my local server (xampp), everything works fine.
• When I try to send a mail from a real apache server, the mail is correctly sent, but the content is empty. Everything else is fine, though (sender, recipient, CC, ...).

From the SO questions about this kind of issues, I think that it is related to CRLF, but I can't find exactly where the problem is (and none of the SO questions helped).

This is an example of how I use it :

<?php
    $mail = new Mail();
    $mail->from('** adress **', '** name **');
    $mail->addTo($user->mail);
    $mail->addCC('** CC adress **', '** name **');

    $mail->html = true;
    $mail->subject = '** subject of the mail **';
    $mail->content = '** HTML code **'; // This HTML is valid
    $mail->send();

And here is the class :

<?php
define('CRLF', "
");

// This is used to send mail
class Mail extends Controller
{
    // Boundary
    private $boundary = null;

    // Recipients, RFC 2822
    public $to = [];
    // Subject of the mail, RFC 2047
    public $subject = '';

    // Content of the mail
    public $message = '';
    // Content is HTML ?
    public $html = false;
    // Attachments
    public $attachments = [];

    // Additional headers
    public $headers = [];

    public function __construct()
    {
        $this->boundary = '_'.md5(uniqid(rand())).'_';
        $this->headers = [
            'MIME-Version' => '1.0',
            'Content-Type' => 'multipart/mixed; boundary="'.$this->boundary.'"'
        ];
    }

    public function addTo($mail, $name = null)
    {
        $this->to[] = ($name ? $name.' ' : '').'<'.$mail.'>';
        return $this;
    }

    public function from($mail, $name = null)
    {
        $this->headers['From'] = ($name ? $name.' ' : '').'<'.$mail.'>';
        return $this;
    }

    public function replyTo($mail, $name = null)
    {
        $this->headers['Reply-to'] = ($name ? $name.' ' : '').'<'.$mail.'>';
        return $this;
    }

    public function addCC($mail, $name = null)
    {
        $this->headers['Cc'][] = ($name ? $name.' ' : '').'<'.$mail.'>';
        return $this;
    }

    public function addBC($mail, $name = null)
    {
        $this->headers['Bcc'][] = ($name ? $name.' ' : '').'<'.$mail.'>';
        return $this;
    }

    public function addAttachment($fileName, $name = null)
    {
        $this->attachments[] = [$fileName, ($name === null ? pathinfo($fileName, PATHINFO_FILENAME) : $name)];
        return $this;
    }

    public function send()
    {
        // Add main content
        $fullMessage = '--'.$this->boundary.CRLF.
            'Content-Type: '.($this->html ? 'text/html' : 'text/plain').'; charset=UTF-8'.CRLF.CRLF.
            $this->content;

        // Attachments
        foreach ($this->attachments as $attachment)
        {
            if (!is_readable($attachment[0]))
                throw new Exception('Cannot read file "'.$attachment[0].'"');
            $fullMessage .= CRLF.CRLF.'--'.$this->boundary.$thids->nl.
                'Content-Type: '.mime_content_type($attachment[0]).'; name="'.$attachment[1].'"'.CRLF.
                'Content-Transfer-Encoding: base64'.CRLF.
                'Content-Disposition: attachment; filename="'.$attachment[0].'"'.CRLF.CRLF.
                chunk_split(base64_encode(file_get_contents($attachment[0]))).CRLF;
        }

        // Adding the headers
        $fullHeaders = '';
        foreach ($this->headers as $name => $content)
        {
            if (is_array($content))
                $fullHeaders .= $name.': '.implode(', ', $content).CRLF;
            else
                $fullHeaders .= $name.': '.$content.CRLF;
        }

        return mail(implode(',', $this->to), utf8_decode($this->subject), $fullMessage, $fullHeaders);
    }
}

The problem came from and . I solved it by replacing all the in the content of the mail by (not in the headers).