Postfix base configuration

postfix

sudo apt-get update -y
sudo locale-gen en_US
sudo apt-get install postfix opendkim opendkim-tools sasl2-bin libsasl2-modules libsasl2-modules-sql libopendbx1-pgsql iptables-persistent

sudo mkdir /etc/postfix/ssl
cd /etc/postfix/ssl/
sudo openssl genrsa -des3 -rand /etc/hosts -out smtpd.key 1024
sudo chmod 600 smtpd.key
sudo openssl req -new -key smtpd.key -out smtpd.csr
sudo openssl x509 -req -days 3650 -in smtpd.csr -signkey smtpd.key -out smtpd.crt
sudo openssl rsa -in smtpd.key -out smtpd.key.unencrypted
sudo mv -f smtpd.key.unencrypted smtpd.key
sudo openssl req -new -x509 -extensions v3_ca -keyout cakey.pem -out cacert.pem -days 3650
cd

sudo vim /etc/postfix/sasl/smtpd.conf

# pwcheck_method: auxprop
# auxprop_plugin: sql
# mech_list: PLAIN LOGIN CRAM-MD5 DIGEST-MD5 NTLM
# sql_engine: pgsql
# sql_hostnames: 127.0.0.1
# sql_user: smtp
# sql_passwd: smtp
# sql_database: tynnel
# sql_select: SELECT password FROM smtp_access WHERE username = '%u'

sudo vim /etc/default/saslauthd
# START=yes
# OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd"

sudo mkdir -p /var/spool/postfix/var/run/saslauthd
sudo dpkg-statoverride --add root sasl 710 /var/spool/postfix/var/run/saslauthd
sudo adduser postfix sasl

opendkim-genkey -t -s smtp -d tynnel.com
sudo cp smtp.private /etc/postfix/dkim.key
sudo chown opendkim:opendkim /etc/postfix/dkim.key
cat smtp.txt

sudo vim /etc/opendkim.conf

# SigningTable dsn:pgsql://smtp:[email protected]/tynnel/table=dkim?keycol=domain_name?datacol=id
# KeyTable dsn:pgsql://smtp:[email protected]/tynnel/table=dkim?keycol=id?datacol=domain_name,selector,private_key
# SigningTable       /etc/opendkim/SigningTable
# KeyTable           /etc/opendkim/KeyTable
# ExternalIgnoreList /etc/opendkim/TrustedHosts
# InternalHosts      /etc/opendkim/TrustedHosts
# KeyFile /etc/postfix/dkim.key
# Selector smtp
# Canonicalization relaxed/relaxed
# SOCKET inet:8891@localhost

sudo vim /etc/opendkim/TrustedHosts

# 127.0.0.1
# localhost
# 192.168.0.1/24
# x.x.x.x

sudo vim /etc/opendkim/KeyTable

# smtp._domainkey.tynnel.com tynnel.com:smtp:/etc/postfix/dkim.key

sudo vim /etc/opendkim/SigningTable

# * smtp._domainkey.tynnel.com

sudo vim /etc/default/opendkim

# SOCKET="inet:8891@localhost"

sudo adduser postfix opendkim
sudo mkdir /var/spool/postfix/var/run/opendkim
sudo chown opendkim:opendkim /var/spool/postfix/var/run/opendkim
sudo dpkg-statoverride --add root sasl 710 /var/spool/postfix/var/run/opendkim

sudo vim /etc/postfix/main.cf

# inet_interfaces = 172.31.9.253
# inet_protocols = ipv4
# message_size_limit = 20480000

# milter_default_action = accept
# milter_protocol = 6
# smtpd_milters = inet:localhost:8891
# non_smtpd_milters = inet:localhost:8891

# smtpd_sasl_local_domain =
# smtpd_sasl_auth_enable = yes
# smtpd_sasl_security_options = noanonymous
# broken_sasl_auth_clients = yes
# smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination
# smtpd_tls_auth_only = no
# smtp_use_tls = yes
# smtpd_use_tls = yes
# smtp_tls_note_starttls_offer = yes
# smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
# smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
# smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
# smtpd_tls_loglevel = 1
# smtpd_tls_received_header = yes
# smtpd_tls_session_cache_timeout = 3600s
# tls_random_source = dev:/dev/urandom

# debugger_command =
#          PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
#          ddd $daemon_directory/$process_name $process_id & sleep 5

postconf | grep nis:
sudo postconf -e alias_maps=hash:/etc/aliases
sudo postmap aliases
sudo postalias /etc/aliases

sudo /etc/init.d/saslauthd start
sudo service opendkim start
sudo service postfix restart

sudo postmulti -e init
sudo postmulti -I postfix-2 -G outgoing -e create
sudo touch /etc/postfix-2/dynamicmaps.cf
sudo postmulti -i postfix-2 -e enable
sudo rm /etc/postfix-2/main.cf
sudo vim /etc/postfix-2/main.cf

# inet_interfaces = 172.31.1.67
# data_directory = /var/lib/postfix-2
# inet_protocols = ipv4
# master_service_disable = inet
# queue_directory = /var/spool/postfix-2
# multi_instance_group = outgoing
# multi_instance_name = postfix-2
# multi_instance_enable = yes

# --- postfix/main.cf content ---

sudo iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 5 --packet 0 -j SNAT --to-source 172.31.9.253
sudo iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 5 --packet 0 -j SNAT --to-source 172.31.10.125
sudo iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 5 --packet 0 -j SNAT --to-source 172.31.10.172
sudo iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 5 --packet 0 -j SNAT --to-source 172.31.1.67

sudo iptables-save > /etc/iptables/rules.v4

dig smtp._domainkey.tynnel.com TXT
sudo apt-get install swaks
swaks -t [email protected] -f [email protected] (You can test by simply sending an email to [email protected] or [email protected])