TUTORIAL: http://freelinuxtutorials.com/quick-tips-and-tricks/configure-postfix-to-use-gmail-in-rhelcentos/


usuario@wicope:~$ ssh root@192.168.1.121
Last login: Thu Jul 23 10:17:09 2015 from 192.168.1.110
[root@a3ee360fa35a ~]# vi /etc/postfix/main.cf
[root@a3ee360fa35a ~]# service postfix restart
Shutting down postfix:                                     [FAILED]
Starting postfix:                                          [  OK  ]
[root@a3ee360fa35a ~]# yum install cyrus-sasl-plain
Failed to set locale, defaulting to C
Complementos cargados:fastestmirror
Configurando el proceso de instalaci?n
Loading mirror speeds from cached hostfile
epel/metalink                                                                     |  24 kB     00:00
 * base: mirror.trueinter.net
 * epel: mirror1.babylon.network
 * extras: mirror.trueinter.net
 * updates: mirror.trueinter.net
Tuleap                                                                            | 2.9 kB     00:00
base                                                                              | 3.7 kB     00:00
epel                                                                              | 4.4 kB     00:00
epel/primary_db                                                                   | 6.7 MB     00:02
extras                                                                            | 3.4 kB     00:00
updates                                                                           | 3.4 kB     00:00
Resolviendo dependencias
--> Ejecutando prueba de transacci?n
---> Package cyrus-sasl-plain.x86_64 0:2.1.23-15.el6_6.2 will be instalado
--> Resoluci?n de dependencias finalizada

Dependencias resueltas

=========================================================================================================
 Paquete                      Arquitectura       Versi?n                       Repositorio         Tama?o
=========================================================================================================
Instalando:
 cyrus-sasl-plain             x86_64             2.1.23-15.el6_6.2             updates              31 k

Resumen de la transacci?n
=========================================================================================================
Instalar       1 Paquete(s)

Tama?o total de la descarga: 31 k
Tama?o instalado: 37 k
Est? de acuerdo [s/N]:s
Descargando paquetes:
cyrus-sasl-plain-2.1.23-15.el6_6.2.x86_64.rpm                                     |  31 kB     00:00
Ejecutando el rpm_check_debug
Ejecutando prueba de transacci?n
La prueba de transacci?n ha sido exitosa
Ejecutando transacci?n
  Instalando    : cyrus-sasl-plain-2.1.23-15.el6_6.2.x86_64                                          1/1
  Verifying     : cyrus-sasl-plain-2.1.23-15.el6_6.2.x86_64                                          1/1

Instalado:
  cyrus-sasl-plain.x86_64 0:2.1.23-15.el6_6.2

?Listo!
[root@a3ee360fa35a ~]# vi /etc/postfix/main.cf
[root@a3ee360fa35a ~]# mkdir /etc/postfix/sasl
[root@a3ee360fa35a ~]# vi /etc/postfix/sasl/passwd
[root@a3ee360fa35a ~]# chmod 600 /etc/postfix/sasl/passwd
[root@a3ee360fa35a ~]# postmap /etc/postfix/sasl/passwd
[root@a3ee360fa35a ~]#
[root@a3ee360fa35a ~]# cd /etc/pki/tls/certs
[root@a3ee360fa35a certs]# make hostname.pem
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
umask 77 ; \
	PEM1=`/bin/mktemp /tmp/openssl.XXXXXX` ; \
	PEM2=`/bin/mktemp /tmp/openssl.XXXXXX` ; \
	/usr/bin/openssl req  -newkey rsa:2048 -keyout $PEM1 -nodes -x509 -days 365 -out $PEM2 -set_serial 0 ; \
	cat $PEM1 >  hostname.pem ; \
	echo ""    >> hostname.pem ; \
	cat $PEM2 >> hostname.pem ; \
	rm -f $PEM1 $PEM2
Generating a 2048 bit RSA private key
.........................+++
......+++
writing new private key to '/tmp/openssl.xYIt1F'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
......data
[root@a3ee360fa35a certs]# cp /etc/pki/tls/certs/hostname.pem /etc/postfix/cacert.pem
[root@a3ee360fa35a certs]#
[root@a3ee360fa35a certs]# # Borrar log
[root@a3ee360fa35a certs]# echo "" > /var/log/maillog
[root@a3ee360fa35a certs]# echo "" > /var/spool/mail/root
[root@a3ee360fa35a certs]# # Borrar cola de email
[root@a3ee360fa35a certs]# postsuper -d ALL
[root@a3ee360fa35a certs]# # Enviar email
[root@a3ee360fa35a certs]# #echo "Body" | mail -s "Title NO SPAM" "alfreditospowerspam@gmail.com"
[root@a3ee360fa35a certs]# echo "Body" | mail -s "Title NO SPAM" "alfreditospower@gmail.com"
[root@a3ee360fa35a certs]# sleep 3
[root@a3ee360fa35a certs]# cat /var/log/maillog

[root@a3ee360fa35a certs]# cat /var/spool/mail/root

[root@a3ee360fa35a certs]# # Ver configuración de /etc/postfix/main.cf:
[root@a3ee360fa35a certs]# postconf -n
alias_database = hash:/etc/aliases,hash:/etc/aliases.codendi,hash:/etc/aliases.codendi,hash:/etc/aliases.codendi
alias_maps = hash:/etc/aliases,hash:/etc/aliases.codendi,hash:/etc/aliases.codendi,hash:/etc/aliases.codendi
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
debug_peer_level = 2
html_directory = no
inet_interfaces = localhost
inet_protocols = all
mail_owner = postfix
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
mydestination = $myhostname, localhost.$mydomain, localhost
myhostname = localhost
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES
relayhost = [smtp.gmail.com]:587
sample_directory = /usr/share/doc/postfix-2.6.6/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl/passwd
smtp_sasl_security_options = noanonymous
smtp_tls_CAfile = /etc/postfix/cacert.pem
smtp_use_tls = yes
unknown_local_recipient_reject_code = 550
[root@a3ee360fa35a certs]# # To list  the  mail queue:
[root@a3ee360fa35a certs]# mailq
Mail queue is empty
[root@a3ee360fa35a certs]#


BEFORE...
# Go to gmail:
https://www.google.com/settings/security/lesssecureapps
Acceso de aplicaciones menos seguras: Activar <--------- (ACTIVE)