I found out a better way to do this: Check Gmail IMAP via PHP for new mesages in a loop
I use Google to administer my e-mails and I run Nginx + PHP. If I want to check incoming mail to interact with each message subject (to trigger an action), as far as I know, I have only two options: 1) access Google via IMAP PHP / cron job or 2) forward the messages to my server where I can have a subdomain set to pipe the messages to a PHP script. Frankly, I'd preffer the first option because I have already all the IMAP functions tested and done. And if the second solution is really the best, I'd preffer to use Postfix. However, id like some light from somebody who has already browsed this unknown waters. Thank you.