Secure_Outgoing_SMTP_via_Postfix,_Courier,_TLS_and_SASL

For more recent setup with Debian Bullseye, please see: secure_smtpd_using_postfix_and_sasl

Note: Details below are old and may not apply

*OK. First off: apt-get

 apt-get install postfix-tls libsasl2-2 sasl2-bin libsasl2-modules

Main Website used for Config: http://www.falkotimme.com/howtos/perfect_setup_debian_sarge/index.php

Secondard Website - however uses a different Auth file: http://www.tribulaciones.org/docs/postfix-sasl-tls-howto.html

More Good Info & a SIMPLE WAY TO OVERCOME CHROOT → http://wiki.ev-15.com/debian:mail_system

A lot of the following is old and not required in debian squeeze: *Configing: /etc/postfix/main.cf /etc/postfix/sasl/smtpd.conf /etc/postfix/ssl/* - tls certs 1. # SASL Support 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 2. # SASL Auth vi /etc/postfix/sasl/smtpd.conf pwcheck_method: saslauthd mech_list: plain login 3. # TLS Certs mkdir /etc/postfix/ssl cd /etc/postfix/ssl/ openssl genrsa -des3 -rand /etc/hosts -out smtpd.key 1024 chmod 600 smtpd.key openssl req -new -key smtpd.key -out smtpd.csr openssl x509 -req -days 3650 -in smtpd.csr -signkey smtpd.key -out smtpd.crt openssl rsa -in smtpd.key -out smtpd.key.unencrypted mv -f smtpd.key.unencrypted smtpd.key openssl req -new -x509 -extensions v3_ca -keyout cakey.pem -out cacert.pem -days 3650 # TLS Config in /etc/postfix/main.cf # Moving onto TLS on its own. smtpd_tls_auth_only = yes 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

 vi /etc/postfix/main.cf
 #add in
 smtpd_sasl_auth_enable = yes
 #Then try and send emails via smtpd

*Restart Postfix

Now continuing onto Auth

Because postfix runs chrooted - need to move the /var/run dir

 mkdir -p /var/spool/postfix/var/run/saslauthd
 rm -fr /var/run/saslauthd

Edit /etc/default/saslauthd

 Remove # in front of START=yes
 Add the line <del>PARAMS</del>OPTIONS="-m /var/spool/postfix/var/run/saslauthd"

Edit /etc/init.d/saslauthd

Add a # to dir=`dpkg-statoverride –list $PWDIR` Add in dir=“…. below the PIDFILE entry #dir=`dpkg-statoverride –list $PWDIR` Change PWDIR and PIDFILE to the following: PWDIR=”/var/spool/postfix/var/run/${NAME}“ PIDFILE=“${PWDIR}/saslauthd.pid” dir=“root sasl 755 ${PWDIR}”

 #change to:
 createdir root sasl 755 $RUN_DIR

***Save & Close**
***restart saslauthd**
***/etc/init.d/saslauthd start**
***MAKE SURE TO ADJUST FIREWALL - OPEN UP PORT 111 Locally**

Debugging and testing

 user@otherserver:~$ telnet mail.burkesys.com 25
 Trying 78.47.9.122...
 Connected to mail.burkesys.com.
 Escape character is '^]'.
 220 mail.burkesys.com ESMTP Postfix (Debian/GNU)
 ehlo localhost
 250-mail.burkesys.com
 250-PIPELINING
 250-SIZE 20000000
 250-ETRN
 250-STARTTLS
 250-ENHANCEDSTATUSCODES
 250-8BITMIME
 250 DSN

After connecting via telnet, type “ehlo localhost” and watch for the “STARTTLS” line. This *should* show up.

Of course o2 have started filtering external traffic over port 25, and filterting out the starttls which makes life difficult for thunderbird. See: http://markmail.org/message/v5uofqpx5l5pu4rm Just as well I have port 587 open for use with a nice iptable rule:

 iptables -t nat -A PREROUTING -p tcp --dport 587 -j DNAT --to ip.address:25
 iptables -t nat -L
 iptables -t nat -D PREROUTING 1