通过代理检查电子邮件

I've got some code that checks a mailserver for an existence of an email address.

I use something like this to open the connection directly.

fsock = @fsockopen($mxhost, 25, $errno, $error, $this->con_timeout)

However, I am unable to figure out how to do the process via a socks proxy with username and password.

Can anyone help me out?

Lets be more concise:

$proxy = "1.2.3.4"; // proxy 
$port = 8080; // proxy port

$fp = fsockopen($proxy,$port); // connect to proxy
fputs($fp, "CONNECT $mailserver:25 ......");

I'm not sure what the fputs syntax should be.

Thanks