mail() doesn't work on new server

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('myWorkingEmail@example.com', '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.