Postfix With SMTP-AUTH And TLS; Dovecot

Install the required packages (Postfix, cyrus-sasl, Dovecot, etc.) like this:
intsalling cyrus-sasl libsasl2 libsasl2-devel libsasl2-plug-plain \
libsasl2-plug-anonymous libsasl2-plug-crammd5 libsasl2-plug-digestmd5 \
libsasl2-plug-gssapi libsasl2-plug-login postfix dovecot

Then run: postconf -e ‘mydestination = /etc/postfix/local-host-names, localhost.$mydomain’
postconf -e ‘smtpd_sasl_local_domain =’
postconf -e ‘smtpd_sasl_auth_enable = yes’
postconf -e ‘smtpd_sasl_security_options = noanonymous’
postconf -e ‘broken_sasl_auth_clients = yes’
postconf -e ‘smtpd_sasl_authenticated_header = yes’
postconf -e ‘smtpd_recipient_restrictions = \
permit_sasl_authenticated, permit_mynetworks,reject_unauth_destination’
postconf -e ‘inet_interfaces = all’
postconf -e ‘mynetworks = 127.0.0.0/8’
touch /etc/postfix/local-host-names

Then we set the hostname in our Postfix installation
(make sure you replace server1 and example.com with your own settings):

postconf -e 'mydomain = example.com'
postconf -e 'myhostname = server1.$mydomain'

Edit /etc/sasl2/smtpd.conf. It should look like this:

mcedit /etc/sasl2/smtpd.conf
# SASL library configuration file for postfix
# all parameters are documented into:
# /usr/share/doc/cyrus-sasl/options.html
# The mech_list parameters list the sasl mechanisms to use,
# default being all mechs found.
mech_list:         plain login
# To authenticate using the separate saslauthd daemon, (e.g. for
# system or ldap users). Also see /etc/sysconfig/saslauthd.
pwcheck_method:    saslauthd
saslauthd_path:    /var/lib/sasl2/mux
# To authenticate against users stored in sasldb.
#pwcheck_method:    auxprop
#auxprop_plugin:    sasldb
#sasldb_path:       /var/lib/sasl2/sasl.db

Optional:

The default authentication mechanism for saslauthd is pam, however on blackPanther OS 9.x there seems to be a bug.
When you send an email, the first one goes through, and as soon as you try to send a second email, saslauthd dies.
You can find messages like this one in /var/log/messages

Oct 9 17:53:42 server1 saslauthd[4460]: server_exit : master exited: 4460

I’ve found the following workaround: open /etc/sysconfig/saslauthd…

mcedit /etc/sysconfig/saslauthd

… and change SASL_AUTHMECH from pam to shadow:

# $Id: saslauthd.sysconfig,v 1.1 2001/05/02 10:55:48 wiget Exp $
# Authentications mechanism (for list see saslauthd -v)
SASL_AUTHMECH=shadow
# Hostname for remote IMAP server (if rimap auth mech is used)
# Ldap configuration file (if ldap auth mech is used)
SASL_MECH_OPTIONS=
# Extra options (for list see saslauthd -h)
SASLAUTHD_OPTS=

Optional End

Create the SSL certificate needed for TLS:

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

… and configure Postfix for TLS:

postconf -e 'smtpd_tls_auth_only = no'
postconf -e 'smtp_use_tls = yes'
postconf -e 'smtpd_use_tls = yes'
postconf -e 'smtp_tls_note_starttls_offer = yes'
postconf -e 'smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key'
postconf -e 'smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt'
postconf -e 'smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem'
postconf -e 'smtpd_tls_loglevel = 1'
postconf -e 'smtpd_tls_received_header = yes'
postconf -e 'smtpd_tls_session_cache_timeout = 3600s'
postconf -e 'tls_random_source = dev:/dev/urandom'

Next we must configure Dovecot to serve the protocols imap, imaps, pop3, and pop3s.
Open /etc/dovecot.conf and adjust the following values:

mcedit /etc/dovecot.conf
[...]
# Protocols we want to be serving: imap imaps pop3 pop3s
# If you only want to use dovecot-auth, you can set this to "none".
protocols = imap imaps pop3 pop3s
[...]
disable_plaintext_auth = no
[...]
  pop3_uidl_format = %08Xu%08Xv
[...]

Now we must tell the system to start Dovecot only after ntpd has started because
Dovecot isn’t very forgiving if your system’s time moves backwards while Dovecot is running (see

http://wiki.dovecot.org/TimeMovedBackwards
).
This might cause errors like the following in your syslog:

Apr 9 19:29:18 server1 dovecot: Time just moved backwards by 17 seconds.
This might cause a lot of problems, so I’ll just kill myself now.
http://wiki.dovecot.org/TimeMovedBackwards

Unfortunately, on blackPanther OS Dovecot is started before ntpd, so we change it like this:

cd /etc/rc3.d
mv S99ntpd S98ntpd
mv S54dovecot S99dovecot
cd /etc/rc4.d
mv S99ntpd S98ntpd
mv S54dovecot S99dovecot
cd /etc/rc5.d
mv S99ntpd S98ntpd
mv S54dovecot S99dovecot

Then we create the system startup links for Postfix...
chkconfig postfix on

… and (re)start Postfix, saslauthd, and Dovecot:

/etc/init.d/postfix restart
/etc/init.d/saslauthd restart
/etc/init.d/dovecot restart

To see if SMTP-AUTH and TLS work properly now run the following command:

telnet localhost 25

After you have established the connection to your Postfix mail server type

ehlo localhost

If you see the lines

250-STARTTLS

and

250-AUTH PLAIN LOGIN

everything is fine:

[root@server1 rc5.d]# telnet localhost 25
Trying 127.0.0.1…
Connected to localhost.localdomain (127.0.0.1).
Escape character is ‘^]’.
220 server1.example.com ESMTP Postfix (2.5.5) (blackPanther OS)
ehlo localhost
250-server1.example.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
quit
221 2.0.0 Bye
Connection closed by foreign host.
[root@server1 rc5.d]#
quit

to return to the system’s shell.

11.1 Maildir

Dovecot uses Maildir format (not mbox), so if you install ISPConfig on the server,
please make sure you enable Maildir under Management -> Server -> Settings -> Email.
ISPConfig will then do the necessary configuration.

If you do not want to install ISPConfig, then you must configure Postfix to deliver emails to a user’s Maildir
(you can also do this if you use ISPConfig – it doesn’t hurt ;-)):

postconf -e 'home_mailbox = Maildir/'
postconf -e 'mailbox_command ='
/etc/init.d/postfix restart
When I tried this code:
 installing cyrus-sasl libsasl2  \
libsasl2-devel libsasl2-plug-plain libsasl2-plug-anonymous  libsasl2-plug-crammd5 \
libsasl2-plug-digestmd5 libsasl2-plug-gssapi  libsasl2-plug-login postfix dovecot
Very difficult? Try easy server howto! (Later)

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