sendmail mail() ubuntu

[danilevsky]

Hi guys!
I have a problem with sendmail and php function mail()
so, i've installed sendmail
sudo aptitude install sendmail
sudo aptitude install nmap

checking 25 port:
dmitry@danilevsky:~$ nmap -sT localhost

Starting Nmap 4.53 ( http://insecure.org ) at 2008-07-06 21:13 EEST
Interesting ports on drupal (127.0.0.1):
Not shown: 1707 closed ports
PORT STATE SERVICE
22/tcp open ssh
25/tcp open smtp
80/tcp open http
139/tcp open netbios-ssn
445/tcp open microsoft-ds
587/tcp open submission
631/tcp open ipp

Nmap done: 1 IP address (1 host up) scanned in 0.179 seconds

my /etc/php5/apache2/php.ini:
sendmail_path = /usr/sbin/sendmail -t -i

and finaly my php script:
1 <?php
2 if(mail('my@mail.com', 'subject', 'text')) {
3 print 'sent';
4 }
5 else {
6 print 'failed';
7 }
8 ?>

This code returns sent., but no email in my mail...

/var/log/apache2/error.log is empty

What can be the problem?