title: Why does the PHP add extra space in the email body for mail()?
body: <p>Recently I use the <code>mail($to, $subject, $content, $headers)</code> to send email with a very long content including some images link like <a href="http://foo.com/image/1.jpg" rel="nofollow">http://foo.com/image/1.jpg</a>. The problem is that the email body sometimes break at some point and show the link like <a href="http://foo.com/image/1.jp+g" rel="nofollow">http://foo.com/image/1.jp+g</a>, which will break the link. 
  Or sometimes it just break the html tags like break <code>&lt;div&gt;</code> in to <code>&lt; div&gt;</code>, and finally the tag is shown in somewhere that is not supposed to be. Making the email looks so wired.</p>
  
  <p>This problem has bugged me for a whole morning.                      </p>