Own mail server? Would be awesome! If you just ask ‘why’ this tutorial is not for you 😉
Goals:
- own postfix and dovecot server
- support for virtual accounts
- disable system accounts support
- use database as account backend
1. Instalation
#debian/ubuntu apt-get install postfix postfix-mysql dovecot-core dovecot-imapd dovecot-lmtpd dovecot-mysql sasl2-bin
General type of mail configuration: Internet Site
System mail name: domian.name
2. Mysql/MariaDB backend
First prepare backend:
mysqladmin -p create mailserver
mysql -p mailserver
GRANT SELECT ON mailserver.* TO 'mailuser'@'127.0.0.1' IDENTIFIED BY 'mailuserpass';
FLUSH PRIVILEGES;
CREATE TABLE `virtual_domains` (
`id` int(11) NOT NULL auto_increment,
`name` varchar(50) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `virtual_users` (
`id` int(11) NOT NULL auto_increment,
`domain_id` int(11) NOT NULL,
`password` varchar(106) NOT NULL,
`email` varchar(100) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `email` (`email`),
FOREIGN KEY (domain_id) REFERENCES virtual_domains(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `virtual_aliases` (
`id` int(11) NOT NULL auto_increment,
`domain_id` int(11) NOT NULL,
`source` varchar(100) NOT NULL,
`destination` varchar(100) NOT NULL,
PRIMARY KEY (`id`),
FOREIGN KEY (domain_id) REFERENCES virtual_domains(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `mailserver`.`virtual_domains`
(`id` ,`name`)
VALUES
('1', 'example.com'),
('2', 'mail.example.com');
INSERT INTO `mailserver`.`virtual_users`
(`id`, `domain_id`, `password` , `email`)
VALUES
('1', '1', ENCRYPT('123456', CONCAT('$6$', SUBSTRING(SHA(RAND()), -16))), 'mail@example.com');
INSERT INTO `mailserver`.`virtual_aliases`
(`id`, `domain_id`, `source`, `destination`)
VALUES
('1', '1', 'admin@example.com', 'mail@example.com'),
('2', '1', 'webmaster@example.com', 'mail@example.com'),
('3', '1', 'root@example.com', 'mail@example.com');
Most important postfix config file 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/dovecot/dovecot.pem
smtpd_tls_key_file=/etc/dovecot/private/dovecot.pem
smtpd_use_tls=yes
smtpd_tls_auth_only = yes
#Enabling SMTP for authenticated users, and handing off authentication to Dovecot
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions =
permit_sasl_authenticated,
permit_mynetworks,
reject_unauth_destination
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
myhostname = hostname.example.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
#mydestination = example.com, hostname.example.com, localhost.example.com, localhost
mydestination = localhost
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
#Handing off local delivery to Dovecot's LMTP, and telling it where to store mail
virtual_transport = lmtp:unix:private/dovecot-lmtp
#Virtual domains, users, and aliases
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf,
mysql:/etc/postfix/mysql-virtual-email2email.cf
Next let us create configuration files for virtual account support:
#vim /etc/postfix/mysql-virtual-mailbox-domains.cf user = mailuser password = mailuserpass hosts = 127.0.0.1 dbname = mailserver query = SELECT 1 FROM virtual_domains WHERE name='%s' #vim /etc/postfix/mysql-virtual-mailbox-maps.cf user = mailuser password = mailuserpass hosts = 127.0.0.1 dbname = mailserver query = SELECT 1 FROM virtual_users WHERE email='%s' #vim /etc/postfix/mysql-virtual-alias-maps.cf user = mailuser password = mailuserpass hosts = 127.0.0.1 dbname = mailserver query = SELECT destination FROM virtual_aliases WHERE source='%s' #vim /etc/postfix/mysql-virtual-email2email.cf user = mailuser password = mailuserpass hosts = 127.0.0.1 dbname = mailserver query = SELECT email FROM virtual_users WHERE email='%s'
Restart postfix:
service postfix restart
This will test if postfix ‘see’ virtual account from database:
postmap -q example.com mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf postmap -q mail@example.com mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf postmap -q webmaster@example.com mysql:/etc/postfix/mysql-virtual-alias-maps.cf
Next we need to edit other postfix config file master.cf
vim /etc/postfix/master.cf
#
# Postfix master process configuration file. For details on the format
# of the file, see the master(5) manual page (command: "man 5 master").
#
# Do not forget to execute "postfix reload" after editing this file.
#
# ==========================================================================
# service type private unpriv chroot wakeup maxproc command + args
# (yes) (yes) (yes) (never) (100)
# ==========================================================================
smtp inet n - - - - smtpd
#smtp inet n - - - 1 postscreen
#smtpd pass - - - - - smtpd
#dnsblog unix - - - - 0 dnsblog
#tlsproxy unix - - - - 0 tlsproxy
submission inet n - - - - smtpd
-o syslog_name=postfix/submission
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING
smtps inet n - - - - smtpd
-o syslog_name=postfix/smtps
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING
#628 inet n - - - - qmqpd
pickup unix n - - 60 1 pickup
cleanup unix n - - - 0 cleanup
qmgr unix n - n 300 1 qmgr
#qmgr unix n - n 300 1 oqmgr
tlsmgr unix - - - 1000? 1 tlsmgr
rewrite unix - - - - - trivial-rewrite
bounce unix - - - - 0 bounce
defer unix - - - - 0 bounce
trace unix - - - - 0 bounce
verify unix - - - - 1 verify
flush unix n - - 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - - - - smtp
relay unix - - - - - smtp
# -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq unix n - - - - showq
error unix - - - - - error
retry unix - - - - - error
discard unix - - - - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - - - - lmtp
anvil unix - - - - 1 anvil
scache unix - - - - 1 scache
#
# ====================================================================
# Interfaces to non-Postfix software. Be sure to examine the manual
# pages of the non-Postfix software to find out what options it wants.
#
# Many of the following services use the Postfix pipe(8) delivery
# agent. See the pipe(8) man page for information about ${recipient}
# and other message envelope options.
# ====================================================================
#
# maildrop. See the Postfix MAILDROP_README file for details.
# Also specify in main.cf: maildrop_destination_recipient_limit=1
#
maildrop unix - n n - - pipe
flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}
#
# ====================================================================
#
# Recent Cyrus versions can use the existing "lmtp" master.cf entry.
#
# Specify in cyrus.conf:
# lmtp cmd="lmtpd -a" listen="localhost:lmtp" proto=tcp4
#
# Specify in main.cf one or more of the following:
# mailbox_transport = lmtp:inet:localhost
# virtual_transport = lmtp:inet:localhost
#
# ====================================================================
#
# Cyrus 2.1.5 (Amos Gouaux)
# Also specify in main.cf: cyrus_destination_recipient_limit=1
#
#cyrus unix - n n - - pipe
# user=cyrus argv=/cyrus/bin/deliver -e -r ${sender} -m ${extension} ${user}
#
# ====================================================================
# Old example of delivery via Cyrus.
#
#old-cyrus unix - n n - - pipe
# flags=R user=cyrus argv=/cyrus/bin/deliver -e -m ${extension} ${user}
#
# ====================================================================
#
# See the Postfix UUCP_README file for configuration details.
#
uucp unix - n n - - pipe
flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
#
# Other external delivery methods.
#
ifmail unix - n n - - pipe
flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp unix - n n - - pipe
flags=Fq. user=bsmtp argv=/usr/lib/bsmtp/bsmtp -t$nexthop -f$sender $recipient
scalemail-backend unix - n n - 2 pipe
flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store ${nexthop} ${user} ${extension}
mailman unix - n n - - pipe
flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
${nexthop} ${user}
This looked scary but to be sure I included full config file, because there could be changes made in newest version to default config files.
Just reset postfix because we finish configure him 🙂
service postfix restart
3. Dovecot
First we make backup of files that we will edit:
cp /etc/dovecot/dovecot.conf /etc/dovecot/dovecot.conf.orig cp /etc/dovecot/conf.d/10-mail.conf /etc/dovecot/conf.d/10-mail.conf.orig cp /etc/dovecot/conf.d/10-auth.conf /etc/dovecot/conf.d/10-auth.conf.orig cp /etc/dovecot/dovecot-sql.conf.ext /etc/dovecot/dovecot-sql.conf.ext.orig cp /etc/dovecot/conf.d/10-master.conf /etc/dovecot/conf.d/10-master.conf.orig cp /etc/dovecot/conf.d/10-ssl.conf /etc/dovecot/conf.d/10-ssl.conf.orig
Edit dovecot.conf
vim /etc/dovecot/dovecot.conf
---
## Dovecot configuration file
# If you're in a hurry, see http://wiki2.dovecot.org/QuickConfiguration
# "doveconf -n" command gives a clean output of the changed settings. Use it
# instead of copy&pasting files when posting to the Dovecot mailing list.
# '#' character and everything after it is treated as comments. Extra spaces
# and tabs are ignored. If you want to use either of these explicitly, put the
# value inside quotes, eg.: key = "# char and trailing whitespace "
# Default values are shown for each setting, it's not required to uncomment
# those. These are exceptions to this though: No sections (e.g. namespace {})
# or plugin settings are added by default, they're listed only as examples.
# Paths are also just examples with the real defaults being based on configure
# options. The paths listed here are for configure --prefix=/usr
# --sysconfdir=/etc --localstatedir=/var
# Enable installed protocols
!include_try /usr/share/dovecot/protocols.d/*.protocol
protocols = imap lmtp
# A comma separated list of IPs or hosts where to listen in for connections.
# "*" listens in all IPv4 interfaces, "::" listens in all IPv6 interfaces.
# If you want to specify non-default ports or anything more complex,
# edit conf.d/master.conf.
#listen = *, ::
# Base directory where to store runtime data.
#base_dir = /var/run/dovecot/
# Name of this instance. Used to prefix all Dovecot processes in ps output.
#instance_name = dovecot
# Greeting message for clients.
#login_greeting = Dovecot ready.
# Space separated list of trusted network ranges. Connections from these
# IPs are allowed to override their IP addresses and ports (for logging and
# for authentication checks). disable_plaintext_auth is also ignored for
# these networks. Typically you'd specify the IMAP proxy servers here.
#login_trusted_networks =
# Sepace separated list of login access check sockets (e.g. tcpwrap)
#login_access_sockets =
# Show more verbose process titles (in ps). Currently shows user name and
# IP address. Useful for seeing who are actually using the IMAP processes
# (eg. shared mailboxes or if same uid is used for multiple accounts).
#verbose_proctitle = no
# Should all processes be killed when Dovecot master process shuts down.
# Setting this to "no" means that Dovecot can be upgraded without
# forcing existing client connections to close (although that could also be
# a problem if the upgrade is e.g. because of a security fix).
#shutdown_clients = yes
# If non-zero, run mail commands via this many connections to doveadm server,
# instead of running them directly in the same process.
#doveadm_worker_count = 0
# UNIX socket or host:port used for connecting to doveadm server
#doveadm_socket_path = doveadm-server
# Space separated list of environment variables that are preserved on Dovecot
# startup and passed down to all of its child processes. You can also give
# key=value pairs to always set specific settings.
#import_environment = TZ
##
## Dictionary server settings
##
# Dictionary can be used to store key=value lists. This is used by several
# plugins. The dictionary can be accessed either directly or though a
# dictionary server. The following dict block maps dictionary names to URIs
# when the server is used. These can then be referenced using URIs in format
# "proxy::<name>".
dict {
#quota = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext
#expire = sqlite:/etc/dovecot/dovecot-dict-sql.conf.ext
}
# Most of the actual configuration gets included below. The filenames are
# first sorted by their ASCII value and parsed in that order. The 00-prefixes
# in filenames are intended to make it easier to understand the ordering.
!include conf.d/*.conf
# A config file can also tried to be included without giving an error if
# it's not found:
!include_try local.conf
Let us comment and uncomment lines according with this code:
vim /etc/dovecot/conf.d/10-mail.conf
---
mail_location = maildir:/var/mail/vhosts/%d/%n
...
mail_privileged_group = mail
---
vim /etc/dovecot/conf.d/10-auth.conf
--
disable_plaintext_auth = yes
...
auth_mechanisms = plain login
...
#!include auth-system.conf.ext
!include auth-sql.conf.ext
--
vim /etc/dovecot/conf.d/auth-sql.conf.ext
---
passdb {
driver = sql
args = /etc/dovecot/dovecot-sql.conf.ext
}
userdb {
driver = static
args = uid=vmail gid=vmail home=/var/mail/vhosts/%d/%n
}
---
vim /etc/dovecot/dovecot-sql.conf.ext
---
driver = mysql
connect = host=127.0.0.1 dbname=mailserver user=mailuser password=mailuserpass
default_pass_scheme = SHA512-CRYPT
password_query = SELECT email as user, password FROM virtual_users WHERE email='%u';
---
vim /etc/dovecot/conf.d/10-master.conf
---
#default_process_limit = 100
#default_client_limit = 1000
# Default VSZ (virtual memory size) limit for service processes. This is mainly
# intended to catch and kill processes that leak memory before they eat up
# everything.
#default_vsz_limit = 256M
# Login user is internally used by login processes. This is the most untrusted
# user in Dovecot system. It shouldn't have access to anything at all.
#default_login_user = dovenull
# Internal user is used by unprivileged processes. It should be separate from
# login user, so that login processes can't disturb other processes.
#default_internal_user = dovecot
service imap-login {
inet_listener imap {
#port = 0
}
inet_listener imaps {
port = 993
ssl = yes
}
# Number of connections to handle before starting a new process. Typically
# the only useful values are 0 (unlimited) or 1. 1 is more secure, but 0
# is faster. <doc/wiki/LoginProcess.txt>
#service_count = 1
# Number of processes to always keep waiting for more connections.
#process_min_avail = 0
# If you set service_count=0, you probably need to grow this.
#vsz_limit = 64M
}
service pop3-login {
inet_listener pop3 {
port = 0
}
inet_listener pop3s {
#port = 995
#ssl = yes
}
}
service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
mode = 0600
user = postfix
group = postfix
}
# Create inet listener only if you can't use the above UNIX socket
#inet_listener lmtp {
# Avoid making LMTP visible for the entire internet
#address =
#port =
#}
}
service imap {
# Most of the memory goes to mmap()ing files. You may need to increase this
# limit if you have huge mailboxes.
#vsz_limit = 256M
# Max. number of IMAP processes (connections)
#process_limit = 1024
}
service pop3 {
# Max. number of POP3 processes (connections)
#process_limit = 1024
}
service auth {
# auth_socket_path points to this userdb socket by default. It's typically
# used by dovecot-lda, doveadm, possibly imap process, etc. Its default
# permissions make it readable only by root, but you may need to relax these
# permissions. Users that have access to this socket are able to get a list
# of all usernames and get results of everyone's userdb lookups.
unix_listener /var/spool/postfix/private/auth {
mode = 0666
user = postfix
group = postfix
}
unix_listener auth-userdb {
mode = 0600
user = vmail
#group = vmail
}
# Postfix smtp-auth
#unix_listener /var/spool/postfix/private/auth {
# mode = 0666
#}
# Auth process is run as this user.
user = dovecot
}
service auth-worker {
# Auth worker process is run as root by default, so that it can access
# /etc/shadow. If this isn't necessary, the user should be changed to
# $default_internal_user.
user = vmail
}
service dict {
# If dict proxy is used, mail processes should have access to its socket.
# For example: mode=0660, group=vmail and global mail_access_groups=vmail
unix_listener dict {
#mode = 0600
#user =
#group =
}
}
---
vim /etc/dovecot/conf.d/10-ssl.conf
---
ssl = required
...
ssl_cert = </etc/ssl/certs/mail.crt
ssl_key = </etc/ssl/private/mail.key
---
We need to create vmail account
groupadd -g 5000 vmail useradd -g vmail -u 5000 vmail -d /var/mail mkdir -p /var/mail/vhosts/example.com/ chown -R vmail:vmail /var/mail chown -R vmail:dovecot /etc/dovecot chmod -R o-rwx /etc/dovecot
Restart dovecot
service dovecot restart
4. Adding more account to backend
mysql -u root -p mailserver
#domena
INSERT INTO `mailserver`.`virtual_domains`
(`name`)
VALUES
('newdomain.com');
#konto
INSERT INTO `mailserver`.`virtual_users`
(`domain_id`, `password` , `email`)
VALUES
('5', ENCRYPT('newpassword', CONCAT('$6$', SUBSTRING(SHA(RAND()), -16))) , 'email3@newdomain.com');
#alias
INSERT INTO `mailserver`.`virtual_aliases`
(`domain_id`, `source`, `destination`)
VALUES
('5', 'alias@newdomain.com', 'myemail@gmail.com');
#alias Å‚apiÄ…cy wszystko dla domeny
INSERT INTO `mailserver`.`virtual_aliases`
(`domain_id`, `source`, `destination`)
VALUES
('5', '@newdomain.com', 'myemail@gmail.com');
5. SPAM
If you are interested, there are some post about way to fight with spam:
Fight against spam part 1 – Postfix SPF
Fight against spam part 2 – Postfix DKIM
Fight against spam part 3 – Postfix DMARC
Fight against spam part 4 – Postfix SpamAssassin
Fight against spam part 5 – Dovecot Sieve