php mail is not working. Why?

Question

PHP

Hey!
Project in Yii2. Sending mail using the mail function does not work. Os debian 8. Php 5.6
Sending mail from console: echo 123 | exim4 [email protected]
exim 4 started : ps -e | grep exim4
phpinfo:

mail.add_x_header	On	On
mail.force_extra_parameters	no value	no value
mail.log	/var/log/mail.log	/var/log/mail.log
....
sendmail_from	no value	no value
sendmail_path	/usr/sbin/exim4 -t	/usr/sbin/exim4 -t

/var/log/mail.log no errors
I send it like this:

$to      = '[email protected]';
$subject = 'the subject';
$message = 'hello';
$headers = 'From: [email protected]' . "\r\n" ';
var_dump(mail($to, $subject, $message, $headers)); //false

The mail.log indicates that everything is being sent.

Answer 1

I looked at what is in /var/log/exim4/paniclog
. There was also the following:

Unable to set gid=33 or uid(euid=0): forcing real=effective
...

Decided this way:

Nano /etc/apache2/mods-available/mpm_prefork.conf
<IfModule mpm_prefork_module>
…
LimitUIDRange 0 2000
</IfModule>

After that, letters began to arrive immediately.

Answer 2

Try giving the fifth parameter to mail like "[email protected]". Exim probably lacks the sender address and the From field in the headers is not enough for it. Examples are in the help.