0 Install Postfix (SMTP-AUTH and TLS) Courier-IMAPCourier-IMAP-SSL (for IMAPs on port 993) and Courier-POP3Courier-POP3-SSL (for POP3s on port 995)
aptitude install postfix libsasl2-2 sasl2-bin libsasl2-modules procmail
You will be asked two questions. Answer as follows:
General type of mail configuration: <-- Internet Site System mail name: <-- server1.example.com
Then run
dpkg-reconfigure postfix
Again, you'll be asked some questions:
General type of mail configuration: <-- Internet Site System mail name: <-- server1.example.com Root and postmaster mail recipient: <-- [blank] Other destinations to accept mail for (blank for none): <-- server1.example.com, localhost.example.com, localhost.localdomain, localhost Force synchronous updates on mail queue? <-- No Local networks: <-- 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 Use procmail for local delivery? <-- Yes Mailbox size limit (bytes): <-- 0 Local address extension character: <-- + Internet protocols to use: <-- all
Next, do this:
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' echo 'pwcheck_method: saslauthd' >> /etc/postfix/sasl/smtpd.conf echo 'mech_list: plain login' >> /etc/postfix/sasl/smtpd.conf
Afterwards we create the certificates 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
Next we configure Postfix for TLS (make sure that you use the correct hostname for myhostname):
postconf -e 'myhostname = server1.example.com' 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'
The file /etc/postfix/main.cf should now look like this:
cat /etc/postfix/main.cf
# See /usr/share/postfix/main.cf.dist for a commented, more complete version # Debian specific: Specifying a file name will cause the first # line of that file to be used as the name. The Debian default # is /etc/mailname. #myorigin = /etc/mailname smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) biff = no # appending .domain is the MUA's job. append_dot_mydomain = no # Uncomment the next line to generate "delayed mail" warnings #delay_warning_time = 4h readme_directory = no # TLS parameters smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key smtpd_use_tls = yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache # See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for # information on enabling SSL in the smtp client. myhostname = server1.example.com alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = server1.example.com, localhost.example.com, localhost.localdomain, localhost relayhost = mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 mailbox_command = procmail -a "$EXTENSION" mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all inet_protocols = all smtpd_sasl_local_domain = smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous broken_sasl_auth_clients = yes smtpd_sasl_authenticated_header = yes smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination smtpd_tls_auth_only = no smtp_use_tls = yes smtp_tls_note_starttls_offer = yes 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
Authentication will be done by saslauthd. We have to change a few things to make it work properly. Because Postfix runs chrooted in /var/spool/postfix we have to do the following:
mkdir -p /var/spool/postfix/var/run/saslauthd
Now we have to edit /etc/default/saslauthd in order to activate saslauthd. Set START to yes and change the line OPTIONS="-c -m /var/run/saslauthd" to OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd -r":
vi /etc/default/saslauthd
# Settings for saslauthd daemon # Please read /usr/share/doc/sasl2-bin/README.Debian for details. # # Should saslauthd run automatically on startup? (default: no) START=yes # Description of this saslauthd instance. Recommended. # (suggestion: SASL Authentication Daemon) DESC="SASL Authentication Daemon" # Short name of this saslauthd instance. Strongly recommended. # (suggestion: saslauthd) NAME="saslauthd" # Which authentication mechanisms should saslauthd use? (default: pam) # # Available options in this Debian package: # getpwent -- use the getpwent() library function # kerberos5 -- use Kerberos 5 # pam -- use PAM # rimap -- use a remote IMAP server # shadow -- use the local shadow password file # sasldb -- use the local sasldb database file # ldap -- use LDAP (configuration is in /etc/saslauthd.conf) # # Only one option may be used at a time. See the saslauthd man page # for more information. # # Example: MECHANISMS="pam" MECHANISMS="pam" # Additional options for this mechanism. (default: none) # See the saslauthd man page for information about mech-specific options. MECH_OPTIONS="" # How many saslauthd processes should we run? (default: 5) # A value of 0 will fork a new process for each connection. THREADS=5 # Other options (default: -c -m /var/run/saslauthd) # Note: You MUST specify the -m option or saslauthd won't run! # # WARNING: DO NOT SPECIFY THE -d OPTION. # The -d option will cause saslauthd to run in the foreground instead of as # a daemon. This will PREVENT YOUR SYSTEM FROM BOOTING PROPERLY. If you wish # to run saslauthd in debug mode, please run it by hand to be safe. # # See /usr/share/doc/sasl2-bin/README.Debian for Debian-specific information. # See the saslauthd man page and the output of 'saslauthd -h' for general # information about these options. # # Example for postfix users: "-c -m /var/spool/postfix/var/run/saslauthd" #OPTIONS="-c -m /var/run/saslauthd" OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd -r"
Next add the postfix user to the sasl group (this makes sure that Postfix has the permission to access saslauthd):
adduser postfix sasl
Now restart Postfix and start saslauthd:
/etc/init.d/postfix restart /etc/init.d/saslauthd start
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 LOGIN PLAIN
everything is fine. The output on my system looks like this:
root@server1:/etc/postfix/ssl# telnet localhost 25 Trying ::1... Connected to localhost.localdomain. Escape character is '^]'. 220 server1.example.com ESMTP Postfix (Ubuntu) ehlo localhost 250-server1.example.com 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-STARTTLS 250-AUTH LOGIN PLAIN 250-AUTH=LOGIN PLAIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN quit 221 2.0.0 Bye Connection closed by foreign host. root@server1:/etc/postfix/ssl#
Type
quit
to return to the system's shell. Run this to install Courier-IMAP/Courier-IMAP-SSL (for IMAPs on port 993) and Courier-POP3/Courier-POP3-SSL (for POP3s on port 995):
aptitude install courier-authdaemon courier-base courier-imap courier-imap-ssl courier-pop courier-pop-ssl courier-ssl gamin libgamin0 libglib2.0-0
You will be asked two questions:
Create directories for web-based administration? <-- No SSL certificate required <-- Ok
During the installation, the SSL certificates for IMAP-SSL and POP3-SSL are created with the hostname localhost. To change this to the correct hostname (server1.example.com in this tutorial), delete the certificates...
cd /etc/courier rm -f /etc/courier/imapd.pem rm -f /etc/courier/pop3d.pem
... and modify the following two files; replace CN=localhost with CN=server1.example.com (you can also modify the other values, if necessary):
vi /etc/courier/imapd.cnf
[...] CN=server1.example.com [...]
vi /etc/courier/pop3d.cnf
[...] CN=server1.example.com [...]
Then recreate the certificates...
mkimapdcert mkpop3dcert
... and restart Courier-IMAP-SSL and Courier-POP3-SSL:
/etc/init.d/courier-imap-ssl restart /etc/init.d/courier-pop-ssl restart
If you do not want to use ISPConfig, configure Postfix to deliver emails to a user's Maildir*:
postconf -e 'home_mailbox = Maildir/' postconf -e 'mailbox_command =' /etc/init.d/postfix restart
*Please note: You do not have to do this if you intend to use ISPConfig on your system as ISPConfig does the necessary configuration using procmail recipes. But please go sure to enable Maildir under Management -> Server -> Settings -> EMail in the ISPConfig web interface.
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