Thanks for the response on mandrillapp.com. I used to setup this smtp and posfix on my server for hours. Now with mandrillapp and wpmandrill plugin I am super happy and secure. Setupp litteraly took 2min and even a non programmer could do it easily. And even better, it is much less probable that you will end up in spam than using your own serer.
I will use mandrillapp on all my upcoming wp projects.