I'm trying to setup Postfix and Dovecot, the latter with virtual users stored in a MySQL database, following this guide (but here I recap everything as there are some "bugs" in the guide I fixed following the comments). Preamble: I have Postfix, Dovecot, postfix-mysql and dovecot-mysql installed from Ubuntu repositories.
Let's start with Postfix config:
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
readme_directory = no
myhostname = localhost
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
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
relay_domains = *
virtual_alias_maps = proxy:mysql:/etc/postfix/virtual_alias_maps.cf
virtual_mailbox_domains = proxy:mysql:/etc/postfix/virtual_mailbox_domains.cf
virtual_mailbox_maps = proxy:mysql:/etc/postfix/virtual_mailbox_maps.cf
virtual_mailbox_base = /home/vmail
virtual_mailbox_limit = 512000000
virtual_minimum_uid = 5000
virtual_transport = virtual
virtual_uid_maps = static:5000
virtual_gid_maps = static:5000
local_transport = virtual
local_recipient_maps = $virtual_mailbox_maps
transport_maps = hash:/etc/postfix/transport
smtpd_sasl_auth_enable = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = /var/run/dovecot/auth-client
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
smtpd_sasl_security_options = noanonymous
smtpd_sasl_tls_security_options = $smtpd_sasl_security_options
smtpd_tls_auth_only = yes
smtpd_tls_cert_file = /etc/ssl/private/server.crt
smtpd_tls_key_file = /etc/ssl/private/server.key
smtpd_sasl_local_domain = $myhostname
broken_sasl_auth_clients = yes
smtpd_tls_loglevel = 1
Then I created user vmail to store emails:
groupadd -g 5000 vmail
useradd -u 5000 -g vmail -s /usr/bin/nologin -d /home/vmail -m vmail
And MySQL database and user to store info about domains and virtual users:
CREATE DATABASE postfix_db;
USE postfix_db;
CREATE USER postfix_user@localhost IDENTIFIED BY 'password';
GRANT ALL ON postfix_db.* TO postfix_user@localhost;
FLUSH PRIVILEGES;
Then I created the tables related to domains, forwardings and users:
CREATE TABLE `domains` (
`domain` varchar(50) NOT NULL default "",
PRIMARY KEY (`domain`),
UNIQUE KEY `domain` (`domain`)
);
CREATE TABLE `forwardings` (
`source` varchar(80) NOT NULL default "",
`destination` text NOT NULL,
PRIMARY KEY (`source`)
);
CREATE TABLE `users` (
`email` varchar(80) NOT NULL default "",
`password` varchar(20) NOT NULL default "",
`quota` varchar(20) NOT NULL default '20971520',
`domain` varchar(255) NOT NULL default "",
UNIQUE KEY `email` (`email`)
);
I added my domain (which has A and MX records properly set) in the table:
INSERT INTO `domains` VALUES ('virtualdomain.tld');
And an account related to that domain:
INSERT INTO `users` VALUES ('info@virtualdomain.tld', ENCRYPT('password'), '20971520', 'virtualdomain.tld');
Then I created a self-signed cert:
cd /etc/ssl/private/
openssl genpkey -algorithm RSA -pkeyopt rsa_keygen_bits:2048 -out server.key
chmod 400 server.key
openssl req -new -key server.key -out server.csr
openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
chmod 444 server.crt
And then the files I was referring to in Postfix config:
/etc/postfix/virtual_alias_maps.cf
user = postfix_user
password = hunter2
hosts = localhost
dbname = postfix_db
table = domains
select_field = domain
where_field = domain
/etc/postfix/virtual_mailbox_domains.cf
user = postfix_user
password = hunter2
hosts = localhost
dbname = postfix_db
table = forwardings
select_field = destination
where_field = source
/etc/postfix/virtual_mailbox_maps.cf
user = postfix_user
password = hunter2
hosts = localhost
dbname = postfix_db
table = users
select_field = concat(domain,'/',email,'/')
where_field = email
And then
touch /etc/postfix/transport
postmap /etc/postfix/transport
Now I deleted the default Dovecot config file, replacing it with:
protocols = imap
auth_mechanisms = plain
passdb {
driver = sql
args = /etc/dovecot/dovecot-sql.conf
}
userdb {
driver = sql
args = /etc/dovecot/dovecot-sql.conf
}
service auth {
unix_listener auth-client {
group = postfix
mode = 0660
user = postfix
}
user = root
}
mail_home = /home/vmail/%d/%u
mail_location = maildir:~
ssl_cert = </etc/ssl/private/server.crt
ssl_key = </etc/ssl/private/server.key
I created the /etc/dovecot/dovecot-sql.conf file:
driver = mysql
connect = host=localhost dbname=postfix_db user=postfix_user password=hunter2
# The new name for MD5 is MD5-CRYPT so you might need to change this depending on version
default_pass_scheme = MD5-CRYPT
# Get the mailbox
user_query = SELECT '/home/vmail/%d/%u' as home, 'maildir:/home/vmail/%d/%u' as mail, 5000 AS uid, 5000 AS gid, concat('dirsize:storage=', quota) AS quota FROM users WHERE email = '%u'
# Get the password
password_query = SELECT email as user, password, '/home/vmail/%d/%u' as userdb_home, 'maildir:/home/vmail/%d/%u' as userdb_mail, 5000 as userdb_uid, 5000 as userdb_gid FROM users WHERE email = '%u'
# If using client certificates for authentication, comment the above and uncomment the following
#password_query = SELECT null AS password, ‘%u’ AS user
... and finally restarted dovecot and postfix:
service postfix dovecot restart
The problem is that when I try to send an email to info@virtualdomain.tld, I see this in logs:
NOQUEUE: reject: RCPT from blablabla.com[xxx.xxx.xxx.xxx]: 451 4.3.0 <info@virtualdomain.tld>: Temporary lookup failure; from=<my@email.tld> to=<info@virtualdomain.tld> proto=ESMTP helo=<blablabla.com>
And the mail bounces back with the error
550 5.1.1 "Recipient address rejected: User unknown in virtual alias table"
