mail() doesn't work on new server

Question

May be it's a dumb question, but I can't find the reason why php mail function doesn't work I have a nginx server on debian squeeze, I moved to it recently. I tried simple mail execution but it return false.

if(mail('[email protected]', 'test-subject', 'test-text-blablabla'))
   echo 'ok';
else
   echo 'bad';

What can i do with it?

Thanks.

my mail section of php.ini:

[mail function]
; For Win32 only.
; http://php.net/smtp
SMTP = localhost
; http://php.net/smtp-port
smtp_port = 25

; For Win32 only.
; http://php.net/sendmail-from
;sendmail_from = [email protected] 

; For Unix only.  You may supply arguments as well (default: "sendmail -t -i").
; http://php.net/sendmail-path
;sendmail_path =

; Force the addition of the specified parameters to be passed as extra parameters
; to the sendmail binary. These parameters will always replace the value of
; the 5th parameter to mail(), even in safe mode.
;mail.force_extra_parameters =

; Add X-PHP-Originating-Script: that will include uid of the script followed by the filename
mail.add_x_header = On

; The path to a log file that will log all mail() calls. Log entries include
; the full path of the script, line number, To address and headers.
;mail.log =

Solution

Okay, I made it. How I made it for debian squeeze with nginx server: (all commands I execute from root user)

First of all you need to install sendmail

apt-get install sendmail

next, you must configure this file that was easier than I thought

sendmailconfig 

okay, next step that I make was a php.ini configuration (I'm not a great admin, I'm a beginner, so I don't know is it necessary or not.)

I set

sendmail_path= /usr/sbin/sendmail -t -i

Okay, from this moment, theoretically, you can send email, but for my case it led to 504 http error gateway time-out. But as I found much later the email already came to email box. So, my test php file is:

<?php 
   mail('[email protected]', 'test', 'you done that');
   echo 'ok'; // I use this to check that script is end the execution 
?>

That's pretty clear.

Next problem is 504 error. I go to the log files

nano /var/log/mail.log

and here i find this error (that not the only one error, but that one is responsible for 504 error):

sm-msp-queue[***]: My unqualified host name (myhostname) unknown; sleeping for retry

Then, to find how I can solve this trouble: http://forums.fedoraforum.org/archive/index.php/t-85365.html last comment on that page.

Or another words I made this:

nano /etc/hosts

and in that file I change the order of the hosts

127.0.0.1 my_ip localhost myhostname 

save, done. open your test php file, there is no any 504 error and emails is income to email you mention in mail function. As I say, I'm a novice, and that may not work for you, but it work for me anyhow. This is not the end configuration, of course. Hope you find it helpful.