Ubuntu :: Fatal - Postfix Command Reserved For Superuser

I'm trying to change the owner of a /var/www/example/var I've changed all the /var content (chown www-data /var instead of chown www-data var ). I tried executing chown root /var, but now I have problems with Postfix...

In my webpages I use different commands to send mails:
- The phpMailer class
- The mail() command
The phpmailer is working, but not mail()

When I try mail() I've these messages in /var/log/mail.log:
Code:
Dec 30 09:42:31 zeus postfix[3829]: error: to submit mail, use the Postfix sendmail command
Dec 30 09:42:31 zeus postfix[3829]: fatal: the postfix command is reserved for the superuser
Terminal mail command is not working either.

In my /etc/php5/apache2/php.ini I've this configuration:
Code:
[mail function]
; For Win32 only.
; [URL]
;SMTP = localhost
; http://php.net/smtp-port
;smtp_port = 25
; For Win32 only.
; [URL]
;sendmail_from = dstreich.girona.ics@gencat.cat
; For Unix only. You may supply arguments as well (default: "sendmail -t -i").
; [URL]
sendmail_path = /usr/sbin/postfix
I also tried sendmail -t -i without luck.