Postfix : track spam complaints like common email marketing tools

I use Postfix and PHPMailer today to send emails and I wondered if it possible to track spam complaints. Here is what I tried so far :

I check the Postfix mail.log file and I read the dsn to know the email status. Then I know if the email was received (staus=sent) or if there is a transitory failure or permanent failure in delivery (status=bounced) : OKAY

Now I would like to know if there is any spam complaint..

For example Campain Monitor says :

I wondered where email marketing tools go to find this data ?

Any idea ?

The way you get to find out about spam complaints is via feedback loops or FBLs. These are designated addresses on your server to which large ISPs will send notifications about messages reported as spam. To yoru mail server they look like any other inbound message, and they are not bounces. You will need to receive the message (perhaps by piping it to a script, which postfix can do easily), then parse it and decide what to do.

Most feedback loops send notifications in RFC5965 ARF format which is easy to parse. Yahoo has some strict requirements for their feedback loop - you must have SPF and DKIM signing set up.

There is a good list of ISPs and feedback loops here.