3

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"
  • What's the result of command postmap -q virtualdomain.tld mysql:/etc/postfix/virtual_alias_maps.cf and postmap -q virtualdomain.tld mysql:/etc/postfix/virtual_mailbox_domains.cf? Please also check maillog after you run those commands. – masegaloeh Oct 31 '14 at 23:41
  • Thanks for the reply. Here are the results: root:~# postmap -q virtualdomain.tld mysql:/etc/postfix/virtual_alias_ maps.cf virtualdomain.tld root:~# postmap -q virtualdomain.tld mysql:/etc/postfix/virtual_mailbox_domains.cf (empty) Better in pastebin: pastebin.com/raw.php?i=66UGqx9L Nothing in server logs – MultiformeIngegno Nov 1 '14 at 1:00
  • 1
    As you said, the tutorial is broken (duh!). Remember, you should consult official documentation whenever you using any tutorial to getting started. – masegaloeh Nov 1 '14 at 1:12
3

Looks like, your virtual_alias_maps and virtual_mailbox_domains was swapped. Try to rename them

mv /etc/postfix/virtual_alias_maps.cf /tmp/virtual_mailbox_domains.tmp
mv /etc/postfix/virtual_mailbox_domains.cf /etc/postfix/virtual_alias_maps.cf 
mv /tmp/virtual_mailbox_domains.tmp /etc/postfix/virtual_mailbox_domains.cf

Don't forget to run postfix reload.

  • Ooook!!! Something seems to start working now!! I can see the mail in /home/vmail/virtualdomain.tld/info@virtualdomain.tld/new. And here's the syslog: pastebin.com/raw.php?i=pAf3VL2V. But if I try to connect from an email client specifying my FQDN as host and username&password specified in "users" table I get these errors in syslog "Auth failed. TLS: Disconnected" "warning: SASL: Connect to /var/run/dovecot/auth-client failed: No such file or directory" and "fatal: no SASL authentication mechanisms" – MultiformeIngegno Nov 1 '14 at 2:30
  • If I set PLAIN instead of MD5-CRYPT everything works I can even access from my external client. Seems MySQL ENCRYPT function used when adding the password to the users table isn't encrypting as MD5 (it doesn't even start with $1)... mmm – MultiformeIngegno Nov 1 '14 at 2:52
2

I'm sure Dovecot is the one that creates the auth file, as postfix talks to dovecot and dovecot does the authentication so in your 'dovecot.conf' add:

path = /var/run/dovecot/auth-client

into the client block like so:

service auth {
    unix_listener auth-client {
        path = /var/run/dovecot/auth-client
        group = postfix
        mode = 0660
        user = postfix
    }

or

service auth {
    unix_listener /var/run/dovecot/auth-client {
        group = postfix
        mode = 0660
        user = postfix
    }

Restart dovecot

Check if /var/run/dovecot/auth-client is created

type in ls -l /var/run/dovecot/auth-client to confirm.

Then retry.

  • I found the correct dirs. Apparently since ubuntu 12.04 the path is /var/spool/postfix/private/auth. Now the only problem seems to be the MD5 encrypt function by MySQL. When I insert the data in "users" table ENCRYPT('password') doesn't actually store the password as MD5-CRYPT scheme.. Which function should I use instead? – MultiformeIngegno Nov 1 '14 at 3:35
  • Your Password row varchar(20) doesn't seem enough for the md5-crypt hash: password varchar(20) NOT NULL default "" Change the varchar length value to varchar(64) – devatnull Nov 1 '14 at 4:00
  • Thanks. I'll try as soon as the screenshot of the VPS is complete. :D – MultiformeIngegno Nov 1 '14 at 4:03
  • BTW MD5 is considered a weak encryption method, once you get the set up working look into another more secure encryption method like sha512/256 etc – devatnull Nov 1 '14 at 4:04
  • Check this post for a reference to a similiar situation: stackoverflow.com/questions/24186158/… – devatnull Nov 1 '14 at 4:12

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