无法通过OpenShift中的php邮件发送邮件

Question

I've been trying out some php codes and I cannot able to send mail through the following code. I've sent some days before but now the mail() function returns true but the mail is not in the recipient's inbox. Here's the code:

$to = "test@example.com";
$subject = "Testing Emails";
$emailBody = "Hello";
$headers = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=iso-8859-1" . "\r\n";
$headers .= "From: Test <no-reply@example.com>" . "\r\n";
$headers .= "Reply-To: no-reply@example.com"."\r\n";
$mail = mail($to,$subject,$emailBody,$headers);

if($mail){    
    echo 'Successfully sent';
} else {
    echo 'Failed to send';
}

Note: I've replaced all the to address with an original address.

Answer 1

From the PHP mail function page

Note:

If messages are not received, try using a LF (\n) only. 
Some Unix mail transfer agents (most notably » qmail) replace LF by CRLF 
automatically (which leads to doubling CR if CRLF is used). 
This should be a last resort, as it does not comply with » RFC 2822.