postfix
HowTo: Authenticated email relay server with Postfix
Setup Postfix as a email relay server which will authenticate with public email server for sending emails. If you want to use a Gmail as a Free SMTP server us, use this as in any of the redhat or ubuntu servers
For Ubuntu
apt-get install postfix mailutils libsasl2-2 ca-certificates libsasl2-modules
Replace the ceritficate file in the configuration
cat /etc/ssl/certs/Thawte_Premium_Server_CA.pem | sudo tee -a /etc/postfix/cacert.pem
If you do not have postfix installed before, postfix configuration wizard will ask you some questions. Just select your server as Internet Site and for FQDN use something like mail.example.com , For Centos
yum install postfix email mailx cyrus-sasl cyrus-sasl-lib cyrus-sasl-plain
[root@server ~]# vi /etc/postfix/main.cf biff = no append_dot_mydomain = no readme_directory = no myhostname = smtpout.innovautelabs.intra mydomain = innovaturelabs.intra myorigin = $mydomain alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases mydestination = localhost.localdomain, , localhost mynetworks = 192.168.1.0/24, 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all relayhost = [smtp.gmail.com]:587 smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl-passwords smtp_sasl_security_options = noanonymous smtp_tls_CAfile = /etc/ssl/certs/ca-bundle.trust.crt smtp_use_tls = yes smtp_tls_loglevel = 1 smtp_tls_security_level = encrypt smtp_sasl_mechanism_filter = login
Now create a password file which should have a valid email and password; onece hashed the password file postfix can read the data in it after that, you can delete the plaintext passwd file. Alternately, if you’d feel better keeping the file around for whatever reason, you can run chmod 600 passwd and make it only readable by its owner, which should be root
vi /etc/postfix/sasl-passwords [smtp.gmail.com]:587 username@gmail.com:password
chmod 600 /etc/postfix/sasl-passwords
postmap /etc/postfix/sasl-passwords
Finally, reload postfix config for changes to take effect:
service postfix restart