webjunk

Should have mentioned that if you want to see if the change took effect, run the script again with phpinfo and see if sendmail_path comes up with the new setting.
The php.ini should be in the root of the WEB-ACCESSIBLE directory but may have to be in your home directory.

Use this version of my mail script:

<?
ini_set ("sendmail_path", "/usr/sbin/sendmail");
mail('tester@YOUREMAIL.COM', 'Test of php email', 'This is only a test');
?>

and then also try:

<?
ini_set ("sendmail_path", "/usr/bin/sendmail");
mail('tester@YOUREMAIL.COM', 'Test of php email', 'This is only a test');
?>

‘tester@YOUREMAIL.COM’ is the TO: fields so it must be where you can receive email.
The function is:
mail(To,Subject,MessageBody,Headers,Parameters)

Only the first three are required. Sometimes you need the sender address (the -f) set to a real known address to avoid outgoing spam filters.

Make a small change to the test script:

<?
mail('tester@YOUREMAIL.COM', 'Test of php email', 'This is only a test', 'From: website@YOURDOMAIN.COM', '-fwebsite@YOURDOMAIN.COM');
?>

Make sure the two website@YOURDOMAIN.COM addresses are a valid email account on that server. No you will not see any results after running the script. Its as basic as you can get. Just using PHP mail to send an email. either you receive it or not. It just eliminates other issues.

you can not be on linux and windows at the same time

Let’s Start from basics:
First create a php file with the following. Call it whatever you want but DO NOT POST IT’S NAME HERE!!! Just try it yourself then delete it.

<?
$headers = 'From: website@YOURDOMAIN.COM';
mail('tester@YOUREMAIL.COM', 'Test of php email', 'This is only a test');
?>

Lastly. Are you keeping this domain name? It expires in three days.

Sorry. Missed the nginx reference. If you have permalinks enabled I think you need this:

if (!-e $request_filename) {
  rewrite ^.*$ /index.php last;
}

or

if (!-e $request_filename) {
rewrite . /index.php last;
}

Don’t deal with nginx often and this is all I have in my own documentation. Otherwise if you do a Google search against this site with nginx.conf you will get a bunch of results. Just honestly do not know enough on nginx to point you to a correct answer but you might be able to recognize it.

587 is the alt port for SMTP. But often its blocked.
WHen you say “other sies” are they on the same server with the same IP #? And using 587?
If you have some kind of shell access to the server you should be able to test the outgoing port. Use this command:
telnet smtp.domainname.com 587

If it says Connected the port is open.