PHP+postfix with Gmail on El Capitan ref: http://qiita.com/kyoh86/items/c09224660da7ed618afd

file1.txt

[smtp.gmail.com]:587 hoge@hoge.com:hogehogehoge

file2.txt

sudo postmap hash:/etc/postfix/sasl_passwd
sudo postfix reload
sudo postfix stop
sudo postfix start

file3.sh

sudo postmap hash:/etc/postfix/sasl_passwd
sudo postfix reload
sudo postfix stop
sudo postfix start

file3.txt

sudo postmap hash:/etc/postfix/sasl_passwd
sudo postfix reload
sudo postfix stop
sudo postfix start

file4.txt

```sample.php
<?php
date_default_timezone_set('Asia/Tokyo');
mb_send_mail(
    "hoge@hoge.com",
    "test for postfix",
    "test for PHP+postfix with Gmail on El Capitan",
    "From: hoge@hoge.com"
);
?>
```

main.cf

# :
# : 前略
# :

# CUSTOM ########
# Minimum Postfix-specific configurations.
mail_owner = _postfix
setgid_group = _postdrop

myhostname = smtp.gmail.com
relayhost=[smtp.gmail.com]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_tls_security_options = noanonymous
smtp_use_tls = yes
smtp_sasl_mechanism_filter = plain

php.ini

;
; 前略
;
[mail function]
; For Win32 only.
; http://php.net/smtp
SMTP = smtp.gmail.com
; http://php.net/smtp-port
smtp_port = 587

; For Win32 only.
; http://php.net/sendmail-from
sendmail_from = hoge@hoge.com

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

; 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().
;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

sample.php

<?php
date_default_timezone_set('Asia/Tokyo');
mb_send_mail(
    "hoge@hoge.com",
    "test for postfix",
    "test for PHP+postfix with Gmail on El Capitan",
    "From: hoge@hoge.com"
);
?>