email — отправка писем с помощью php mail () с использованием postfix и nginx

У меня есть веб-сервер на моем RPI с Nginx. Я хотел бы отправлять электронные письма с функцией php mail (). Я установил postfix и mailutils.
У меня есть следующий скрипт:

<?php
$to      = '[email protected]';
$subject = 'the subject';
$message = 'hello';
$from   =  'From: pi@home';

if (mail($to, $subject, $message, $from)) {
echo '<h2>Thank you for your email!</h2>';
} else {
echo '<h2>Oops! An error occurred. Try sending your message  again.</h2>';
}
?>

Если я выполню это напрямую:

www-data@home ~ $ php -f script.php
<h2>Thank you for your email!</h2>

Но если я загружаю скрипт в веб-страницу, я получаю:

<h2>Oops! An error occurred. Try sending your message again.</h2>

В /var/log/mail.log php -f генерирует:

Jan  7 21:34:11 home postfix/pickup[27836]: A0A65A1E5A: uid=1000 from=<www-data>
Jan  7 21:34:11 home postfix/cleanup[27867]: A0A65A1E5A: message-id=<[email protected]>
Jan  7 21:34:11 home postfix/qmgr[27837]: A0A65A1E5A: from=<[email protected]>, size=332, nrcpt=1 (queue active)
Jan  7 21:34:12 home postfix/smtp[27869]: A0A65A1E5A: to=<[email protected]>, relay=gmail-smtp-in.l.google.com[74.125.195.26]:25, delay=1.3, delays=0.07/0.02/0.79/0.44, dsn=2.0.0, status=sent (250 2.0.0 OK 1452198852 y130si13070628wmy.93 - gsmtp)
Jan  7 21:34:12 home postfix/qmgr[27837]: A0A65A1E5A: removed

но когда я загружаю страницу:

Jan  7 20:40:01 home postfix/pickup[25500]: D50C2A1E54: uid=33 from=<www-data>
Jan  7 20:40:01 home postfix/cleanup[25681]: D50C2A1E54: message-id=<[email protected]>
Jan  7 20:40:01 home postfix/qmgr[25501]: D50C2A1E54: from=<[email protected]>, size=601, nrcpt=1 (queue active)
Jan  7 20:40:02 home postfix/smtpd[25684]: connect from home[ZZZZ]
Jan  7 20:40:02 home postfix/smtp[25683]: warning: host home.YYYY[ZZZZ]:25 greeted me with my own hostname home.YYYY
Jan  7 20:40:02 home postfix/smtp[25683]: warning: host home.YYYY[ZZZZ]:25 replied to HELO/EHLO with my own hostname home.YYYY
Jan  7 20:40:02 home postfix/smtp[25683]: D50C2A1E54: to=<[email protected]>, orig_to=<www-data>, relay=home.YYYY[ZZZZ]:25, delay=0.51, delays=0.07/0.04/0.4/0, dsn=5.4.6, status=bounced (mail for home.YYYY loops back to myself)
Jan  7 20:40:02 home postfix/smtpd[25684]: disconnect from home[ZZZZ]
Jan  7 20:40:02 home postfix/cleanup[25681]: 5AF1EA1E56: message-id=<[email protected]>
Jan  7 20:40:02 home postfix/bounce[25688]: D50C2A1E54: sender non-delivery notification: 5AF1EA1E56
Jan  7 20:40:02 home postfix/qmgr[25501]: 5AF1EA1E56: from=<>, size=2524, nrcpt=1 (queue active)
Jan  7 20:40:02 home postfix/qmgr[25501]: D50C2A1E54: removed
Jan  7 20:40:02 home postfix/smtpd[25684]: connect from home[ZZZZ]
Jan  7 20:40:02 home postfix/smtp[25683]: warning: host home.YYYY[ZZZZ]:25 greeted me with my own hostname home.YYYY
Jan  7 20:40:02 home postfix/smtp[25683]: warning: host home.YYYY[ZZZZ]:25 replied to HELO/EHLO with my own hostname home.YYYY
Jan  7 20:40:02 home postfix/smtp[25683]: 5AF1EA1E56: to=<[email protected]>, relay=home.YYYY[ZZZZ]:25, delay=0.18, delays=0.01/0/0.17/0, dsn=5.4.6, status=bounced (mail for home.YYYY loops back to myself)
Jan  7 20:40:02 home postfix/smtpd[25684]: disconnect from home[ZZZZ]
Jan  7 20:40:02 home postfix/qmgr[25501]: 5AF1EA1E56: removed

Некоторые из моих файлов конфигурации:
/ и т.д. / хосты:

127.0.0.1         localhost
::1               localhost ip6-localhost ip6-loopback
fe00::0         ip6-localnet
ff00::0         ip6-mcastprefix
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters
ZZZZ      home home.YYYY

/ И т.д. / имя хоста

home

/ И т.д. / mailname

home.YYYY

/etc/postfix/main.cf

smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
biff = no

append_dot_mydomain = no

readme_directory = no

# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

myhostname = home.YYYY
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = localhost.localdomain, localhost
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = ipv4

/ И т.д. / Nginx / сайты-доступные / MySite

[...]
location ~ \.php$ {
fastcgi_pass  unix:/var/run/php5-fpm.sock;
fastcgi_index  index.php;
include       fastcgi_params;
}
[...]

Я не могу понять, если это проблема php, postfix, nginx или сети (имена хостов, домены и т. Д.).

Вы можете мне помочь?