Host Email with Postfix, Dovecot and Postgres on Debian 6 (Squeeze)

Recently I had to configure a web server from scratch, which I haven’t done in a while. So I took a look at the guides from my current hosting provider Linode. They have a guide covering debian 5 (Lenny) which is basically the same for debian 6 (squeeze). To make this a bit more exciting I decided to replace MySQL for Postgres since I really didn’t need it. So I will only post about the changes you need to perform based from the Linode guide.

Install Required Packages

Replace the mysql related packages for postgres and replace mailx for bsd-mailx.

apt-get install postfix postfix-pgsql postfix-doc dovecot-common dovecot-imapd dovecot-pop3d postfix-tls libsasl2-2 libsasl2-modules libsasl2-modules-sql sasl2-bin libpam-pgsql openssl telnet bsd-mailx postgresql-contrib postgresql-8.4

Set up Postgres for Virtual Domains and Users

Open /etc/postgres/8.4/main/pg_hba.conf and make sure local connections require a password

host    all         all         127.0.0.1/32          md5

You could also make all local connections trusted and in this case no password will be needed, but of course it could represent a security risk

host    all         all         127.0.0.1/32          trust

This next step is optional but as a security measure I like to have Postgres listen on a diferent port other than the default.

Open /etc/postgres/8.4/main/postgres.conf and uncomment the following line and add 6789 as the port number

port = 6789

Create the user for the mail database.

sudo -u postgres createuser  -P -E -s -d mail_admin

Now create the database.

sudo -u postgres createdb -O mail_admin mail -E UTF-8

Grant all privileges.

GRANT ALL PRIVILEGES ON DATABASE mail to mail_admin;

Create domains, forwardings, users and transport tables.

CREATE TABLE domains (domain varchar(50) NOT NULL, PRIMARY KEY (domain) );
CREATE TABLE forwardings (source varchar(80) NOT NULL, destination TEXT NOT NULL, PRIMARY KEY (source) );
CREATE TABLE users (email varchar(80) NOT NULL, password varchar(20) NOT NULL, PRIMARY KEY (email) );
CREATE TABLE transport ( domain varchar(128) NOT NULL default '', transport varchar(128) NOT NULL default '', constraint fieldomainunique UNIQUE  (domain) );

Now I’ll create a domain and user in mail database. But first I will use Postgres pgcrypto functions since passwords need to be encrypted using the UNIX original encryption scheme. Replace your_password with your own password.

mail=#\i /usr/share/postgresql/8.4/contrib/pgcrypto.sql
INSERT INTO domains (domain) VALUES ('example.com');
INSERT INTO users (email, password) VALUES ('info@example.com', crypt('your_password', gen_salt('des') ));
mail=#\q

Configure Postfix to work with Postgres

Create file /etc/postfix/pgsql-virtual_domains.cf

user = mail_admin
password = mail_admin_password
dbname = mail
query = SELECT domain AS virtual FROM domains WHERE domain='%s'
hosts = 127.0.0.1:6789

Create file /etc/postfix/pgsql-virtual_forwardings.cf

user = mail_admin
password = mail_admin_password
dbname = mail
query = SELECT destination FROM forwardings WHERE source='%s'
hosts = 127.0.0.1:6789

Create file /etc/postfix/pgsql-virtual_mailboxes.cf

user = mail_admin
password = mail_admin_password
dbname = mail
query = SELECT split_part(email, '@', 2) || '/' || split_part(email,'@', 1) FROM users WHERE email='%s';
hosts = 127.0.0.1:6789

Create file /etc/postfix/pgsql-virtual_email2email.cf

user = mail_admin
password = mail_admin_password
dbname = mail
query = SELECT email FROM users WHERE email='%s'
hosts = 127.0.0.1:6789

Set the proper permissions

chmod o= /etc/postfix/pgsql-virtual_*.cf
chgrp postfix /etc/postfix/pgsql-virtual_*.cf

Add the following one line at a time. Replace qualified.hostname.com with your hostname

postconf -e 'myhostname = qualified.hostname.com'
postconf -e 'mydestination = qualified.hostname.com, localhost, localhost.localdomain'
postconf -e 'mynetworks = 127.0.0.0/8'
postconf -e 'message_size_limit = 30720000'
postconf -e 'virtual_alias_domains ='
postconf -e 'virtual_alias_maps = proxy:pgsql:/etc/postfix/pgsql-virtual_forwardings.cf, pgsql:/etc/postfix/pgsql-virtual_email2email.cf'
postconf -e 'virtual_mailbox_domains = proxy:pgsql:/etc/postfix/pgsql-virtual_domains.cf'
postconf -e 'virtual_mailbox_maps = proxy:pgsql:/etc/postfix/pgsql-virtual_mailboxes.cf'
postconf -e 'virtual_mailbox_base = /home/vmail'postconf -e 'virtual_uid_maps = static:5000'postconf -e 'virtual_gid_maps = static:5000'
postconf -e 'smtpd_sasl_auth_enable = yes'postconf -e 'broken_sasl_auth_clients = yes'
postconf -e 'smtpd_sasl_authenticated_header = yes'
postconf -e 'smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination'
postconf -e 'smtpd_use_tls = yes'
postconf -e 'smtpd_tls_cert_file = /etc/postfix/smtpd.cert'
postconf -e 'smtpd_tls_key_file = /etc/postfix/smtpd.key'
postconf -e 'virtual_create_maildirsize = yes'
postconf -e 'virtual_maildir_extended = yes'
postconf -e 'proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps'
postconf -e virtual_transport=dovecotpostconf -e dovecot_destination_recipient_limit=1

Change postfix listening port to 2525 in /etc/postfix/master.cf.

2525      inet  n       -       -       -       -       smtpd

Or you could just uncomment the submission line and default to port 587.

submission inet n       -       -       -       -       smtpd

Configure saslauthd to use Postgres

Create file /etc/pam.d/smtp. Replace your_password with your own password.

auth    required   pam_pgsql.so user=mail_admin passwd=your_password host=127.0.0.1 port=6789 db=mail table=users usercolumn=email passwdcolumn=password crypt=1
account sufficient pam_pgsql.so user=mail_admin passwd=your_password host=127.0.0.1 port=6789 db=mail table=users usercolumn=email passwdcolumn=password crypt=1

Create file /etc/postfix/sasl/smtpd.conf. Replace your_password with your own password.

pwcheck_method: saslauthd
mech_list: plain login
allow_plaintext: true
auxprop_plugin: sql
sql_engine: pgsql
sql_hostnames: 127.0.0.1:6789
sql_user: mail_admin
sql_passwd: your_password
sql_database: mail
sql_select: select password from users where email = '%u'

Create file /etc/pam_pgsql.conf. Replace your_password with your own password.

database = mail
host = localhost
user = mail_admin
password = your_password
table = users
user_column = email
pwd_column = password
pw_type = crypt

Set proper permissions to files.

chmod o= /etc/pam_pgsql.conf
chmod o= /etc/postfix/sasl/smtpd.conf

Configure Dovecot

One thing that was pointed out at the end of the guide by user Nathan  is to change cmusieve for sieve on file /etc/dovecot/dovecot.conf on this following part

protocol lda {
    log_path = /home/vmail/dovecot-deliver.log
    auth_socket_path = /var/run/dovecot/auth-master
    postmaster_address = postmaster@example.com
    mail_plugins = cmusieve #change to sieve
    global_script_path = /home/vmail/globalsieverc
}

Create file /etc/dovecot/dovecot-sql.conf. Replace your_password with your own password.

driver = pgsql
connect = host=127.0.0.1 port=6789 dbname=mail user=mail_admin password=your_password
default_pass_scheme = CRYPT
password_query = SELECT email as user, password FROM users WHERE email='%u';


And thats about it. If you managed to configure everything correctly congratulations!, if not post a comment and we’ll try to find the solution.

Troubleshooting

Remember that /var/log/syslog and /var/log/mail.log are your friends. You can also add the word debug at the end of each line on /etc/pam.d/smtp to help you troubleshoot any problems you may encounter.

 

webjunkie01

 

9 thoughts on “Host Email with Postfix, Dovecot and Postgres on Debian 6 (Squeeze)

  1. good work

    are you sure you did not skip some steps? what about the cert for postfix?

    testing steps along the way would be really terrific – unless you’ve done this several times before the odds of getting through are pretty slim. for example, restarting and testing postfix, etc. it’s unclear exactly which services need to be restarted.

  2. when postfix restarted, many many warnings, eg,

    * Starting Postfix Mail Transport Agent postfix postconf: warning: /etc/postfix/main.cf: unused parameter: virtual_create_maildirsize=yes
    postconf: warning: /etc/postfix/main.cf: unused parameter: virtual_maildir_extended=yes
    postconf: warning: /etc/postfix/main.cf: unused parameter: dovecot_destination_recipient_limit=1
    postconf: warning: /etc/postfix/main.cf: unused parameter: virtual_create_maildirsize=yes

    is this to be expected?

  3. dovcot completely upchucked. apparently they have new dovecot.conf

    relay=dovecot, delay=1383, delays=1383/0.04/0/0.08, dsn=4.3.0, status=deferred (temporary failure. Command output: doveconf: Warning: NOTE: You can get a new clean config file with: doveconf -n > dovecot-new.conf doveconf: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:1: ‘imaps’ protocol is no longer necessary, remove it doveconf: Warning: Obsolete setting in
    /etc/dovecot/dovecot.conf:1: ‘pop3s’ protocol is no longer necessary, remove it doveconf: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:5: ssl_cert_file has been replaced by ssl_cert = <file doveconf: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:6: ssl_key_file has been replaced by ssl_key = <file doveconf: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:8: namespace private {} has been replaced by namespace { type=private } doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf line 19: Unknown setting: global_script_path )

  4. Hello,

    I think that, to be postgres compiant, in pgsql-virtual_mailboxes.cf the query

    SELECT CONCAT(SUBSTRING_INDEX(email,’@’,-1),’/’,SUBSTRING_INDEX(email,’@’,1),’/’) FROM users WHERE email=’%s’

    should be replaced with:

    SELECT split_part(email, ‘@’, 2) || ‘/’ || split_part(email,’@’, 1) FROM users WHERE email=’%s’;

    Thanks for the guide.

    1. Hi Andrea,

      Thanks for the update, it works great. In fact the current SQL statement in pgsql-virtual_mailboxes.cf it’s wrong. It was supposed to be SELECT substring(email from ‘@(.*)’) ||’/’||substring(email from ‘(.*)@’) FROM users WHERE email=’%s’. I’ll add your Postgresql compliant statement.

      Cheers.

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