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:<br>
/etc/postfix/main.cf<br>
/etc/postfix/sasl/smtpd.conf<br>
/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
<br>
# 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<br>
Now continuing onto Auth<br>
Because postfix runs chrooted - need to move the /var/run dir <br>
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