sendmail和php mail（） - “找不到收件人”

Question

I have installed sendmail on my Apache server (Ubuntu)

Everything seems to work find except an email is not beeing sent while using php mail();

I get an error on the Apache errorlog saying:

/usr/sbin/sendmail: no recipients found

This is the way I'm using the function:

$user_email = "[e-mail]";
$headers  = 'MIME-Version: 1.0' . "
";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "
";
$headers .= 'To: ' . $user_email . "
";
$headers .= 'From: Mydomain <[e-mail]>' . "
";

  mail($user_email,"subject","message",$headers);

Answer 1

$user_email = [e-mail]

should be

$user_email = "[e-mail]";