ISP Mail Server HowTo

A Full Service Mail Server

The goal of this document is to describe how to set up postfix, dovecot, clamav, dspam, roundecube, and postfixadmin for a full-featured "ISP" level mail server.

The server must provide:

• multiple virtual domains
• admins for each domain (to add/remove virtual accounts)
• Quota support per domain / account
• downloading email via IMAP / IMAPS / POP3 / POP3S
• relaying email for authenticated users with TLS or SSL (Submission / SMTPS protocol)
• Standard filters (virus/spam/rbl/etc)
• Web mail client
• Value Add services

Set up Lighttpd + PHP

PostfixAdmin needs php pgpsql and imap modules, so we do it in this step.

 apk add lighttpd php php-pgsql php-imap

Stop and remove mini_httpd, and move ACF to lighttpd; We are setting this up to be a mult-domain virtual web server:

 mkdir -p /var/www/domains/host.example.com
 mv  /usr/share/acf/* /var/www/domains/host.example.com

Edit /etc/lighttpd/mod_cgi.conf to serve haserl files by adding a "" => "" cgi handler

$HTTP["url"] =~ "^/cgi-bin/" {
    # disable directory listings
    dir-listing.activate = "disable"
    # only allow cgi's in this directory
    cgi.assign = (
		".pl"	=>	"/usr/bin/perl",
		".cgi"	=>	"/usr/bin/perl",
		"" => ""
	)
}

Edit /etc/lighttpd/mod_fastcgi.conf to serve php scripts

server.modules += ("mod_fastcgi")
fastcgi.server = ( ".php" => ((
                   "socket" =>  "/var/run/lighttpd/lighttpd-fastcgi-php-" + PID + ".socket"
                    "bin-path" => "/usr/bin/php-cgi"
                  ))
                 )
                  

Add these lines to /etc/lighttpd/lighttpd.conf to point to the new document root, and set it up to listen on port 443:

simple-vhost.server-root   = "/var/www/domains/"
simple-vhost.default-host  = "/"
simple-vhost.document-root = "www/

$SERVER["socket"] == "[ip_address_of_server]" {
ssl.engine    = "enable"
ssl.pemfile   = "/etc/lighttpd/server-bundle.pem"
ssl.ca-file   = "/etc/lighttpd/ca-crt.pem"
}

Get a web certificate, and install it. If you want to use a self-signed cert, you can use Generating SSL certs with ACF or Generating SSL certs with ACF 1.9. If you create a certificate with ACF, you can create the "server-bundle.pem" and the "ca-crt.pem" file with these commands:

 openssl x509 -nocerts -nokeys -cacert -in certificate.pfx  -out /etc/lighttpd/ca-crt.pem
 openssl x509 -nodes -in certifcate.pfx -out /etc/lighttpd/server-bundle.pem
 chown root:root /etc/lighttpd/server-bundle.pem
 chmod 400 /etc/lighttpd/server-bundle.pem

Note: The server certifcate and key are in the server-bundle.pem file, so it is critical that the file be read-only by user "root".

Stop and remove mini_httpd; start lighttpd, test

 /etc/init.d/mini_httpd stop
 rc-update del mini_httpd
 apk del mini_httpd
 rc-update add lighttpd
 /etc/init.d/lighttpd start

At this point you should be able to see ACF being served with lighttpd: https://host.example.com/

Install Postgresql

Add get and configure postgresql

 apk add acf-postgresql postgresql-client
 /etc/init.d/postgresql setup
 /etc/init.d/postgresql start
 rc-update add postgresql

At this point any user can connect to the sql server with "trust" mechanism. If you want to enforce password authentication (you probably do) edit /var/lib/postgresql/8.4/data/pg_hba.conf

 Editme: What should we recommend?

Create the postfix database:

 psql -U postgres
  create user postfix with password '******';
  create database postfix owner postfix;
  \c postfix
  create language plpgsql;
  \q

(Of course, use your selected password where ******* is shown above.)

Install PostfixAdmin

We are going to install the postfix admin web front-end before we install the mail server. This just creates an interface to populate the SQL tables that postfix and dovecot will use.

Download PostfixAdmin from Sourceforge. When these instructions were written, 2.3 was the current release, so:

wget http://downloads.sourceforge.net/project/postfixadmin/postfixadmin/postfixadmin_2.3.tar.gz
tar zxvf postfixadmin_2.3.tar.gz
mkdir /var/www/domains/host.example.com/postfixadmin
mv postfixadmin-2.3/* /var/www/domains/host.example.com/postfixadmin
rm -rf postfixadmin*

Edit /var/www/domains/host.example.com/postfixadmin/config.inc.php and modify at least these lines:

$CONF['configured'] = true;
$CONF['setup_password'] = ;  << Don't change this yet
$CONF['database_type'] = 'pgsql';
$CONF['database_host'] = 'localhost';
$CONF['database_user'] = 'postfix';
$CONF['database_password'] = '*****';   << The password you chose above
$CONF['database_name'] = 'postfix';
$CONF['database_prefix'] = ;
$CONF['database_prefix'] = ;
$CONF['database_tables'] = array (
$CONF['admin_email'] = 'you@some.email.com';  << Your email address 
$CONF['encrypt'] = 'md5crypt';
$CONF['authlib_default_flavor'] = 'md5raw';
$CONF['dovecotpw'] = "/usr/sbin/dovecotpw";
$CONF['domain_path'] = 'YES';
$CONF['domain_in_mailbox'] = 'NO';
$CONF['aliases'] = '10';                       
$CONF['mailboxes'] = '10';
$CONF['maxquota'] = '10';
$CONF['quota'] = 'YES';
$CONF['quota_multiplier'] = '1024000';
$CONF['alias_control'] = 'YES';
$CONF['alias_control_admin'] = 'YES';
$CONF['special_alias_control'] = 'YES';
$CONF['fetchmail'] = 'NO';
$CONF['user_footer_link'] = "http://host.example.com";
$CONF['footer_link'] = 'http://host.example.com/postfixadmin/main.php';
$CONF['create_mailbox_subdirs_prefix']='INBOX.';
$CONF['used_quotas'] = 'YES';                     
$CONF['new_quota_table'] = 'YES';

Go to http://host.example.com/postfixadmin/setup.php

Create the password hash, add it to the config.inc.php file

Go back to http://host.example.com/postfixadmin/setup.php

Create superadmin, create a mail domain or other, as desired.

Install Postfix

Create a user for the virtual mail delivery, and get its uid/gid (you'll need the numeric uid/gid for postfix)

adduser vmail -H -D -s /bin/false
grep vmail /etc/passwd

(In examples below, we use 1006/1006 for the uid/gid)

Create the mail directory, and assign vmail as the owner

mkdir -p /var/mail/domains
chown -R vmail:vmail /var/mail/domains

Install postfix

apk add acf-postfix postfix-pgsql

Edit the /etc/postfix/main.cf file Here's an example:

myhostname=host.example.com                                                                  
mydomain=example.com                                                                         
                                                                                                  
mydestination = $myhostname, localhost.$mydomains, localhost                                 
mynetworks_style = subnet                                                                    
mynetworks = 127.0.0.0/8                                                                     
                                                                                                  
virtual_mailbox_domains = proxy:pgsql:/etc/postfix/sql/pgsql_virtual_domains_maps.cf               
virtual_alias_maps = proxy:pgsql:/etc/postfix/sql/pgsql_virtual_alias_maps.cf,                     
       proxy:pgsql:/etc/postfix/sql/pgsql_virtual_alias_domain_maps.cf,                           
       proxy:pgsql:/etc/postfix/sql/pgsql_virtual_alias_domain_catchall_maps.cf                   
                                                                                                  
virtual_mailbox_maps = proxy:pgsql:/etc/postfix/sql/pgsql_virtual_mailbox_maps.cf,                 
       proxy:pgsql:/etc/postfix/sql/pgsql_virtual_alias_domain_mailbox_maps.cf                    
                                                                                                  
virtual_mailbox_base = /var/mail/domains/                                                          
                                                                                                  
virtual_gid_maps = static:1006                                                                     
virtual_uid_maps = static:1006                                                                     
virtual_minimum_uid = 100                                                                          
virtual_transport = virtual     

# This next command means you must create a virtual
# domain for the host itself - ALL mail goes through
# The virtual transport

mailbox_transport = virtual
local_transport = virtual                                                                    
local_transport_maps = $virtual_mailbox_maps                                                 
                                                                                         

smtpd_helo_required = yes                                                                          
disable_vrfy_command = yes                                                                         
message_size_limit = 10240000                                                                      
queue_minfree = 51200000                                                                           
                                                                                                  
smtpd_sender_restrictions =                                                                        
       permit_mynetworks,                                                                         
       reject_non_fqdn_sender,                                                                    
       reject_unknown_sender_domain                                                               
                                                                                                  
smtpd_recipient_restrictions =                                                                     
       reject_non_fqdn_recipient,                                                                 
       reject_unknown_recipient_domain,                                                           
       permit_mynetworks,                                                                         
       permit_sasl_authenticated,                                                                 
       reject_unauth_destination,                                                                 
       reject_rbl_client dnsbl.sorbs.net,                                                         
       reject_rbl_client zen.spamhaus.org,                                                        
       reject_rbl_client bl.spamcop.net                                                           
                                                                                                  
smtpd_data_restrictions = reject_unauth_pipelining    

# we will use this later - This prevents cleartext authentication
# for relaying
smtpd_tls_auth_only = yes 

Now we need to create a *bunch* of files so that postfix can get the delivery information out of sql. Here's a shell script to create the scripts.

cd /etc/postfix mkdir sql PGPW="ChangeMe"

                                                                                                                            cat - <<EOF >sql/pgsql_virtual_alias_domain_catchall_maps.cf

user=postfix password = $PGPW hosts = localhost dbname = postfix query = Select goto From alias,alias_domain where alias_domain.alias_domain = '%d' and alias.address = '@' || alias_domain.target_domain and alias.active = true and alias_domain.active= true EOF cat - <<EOF >sql/pgsql_virtual_alias_domain_mailbox_maps.cf user=postfix password = $PGPW hosts = localhost dbname = postfix query = Select maildir from mailbox,alias_domain where alias_domain.alias_domain = '%d' and mailbox.username = '%u' || '@' || alias_domain.target_domain and mailbox.active = true and alias_domain.active EOF cat - <<EOF >sql/pgsql_virtual_alias_domain_maps.cf user=postfix password = $PGPW hosts = localhost dbname = postfix query = select goto from alias,alias_domain where alias_domain.alias_domain='%d' and alias.address = '%u' || '@' || alias_domain.target_domain and alias.active= true and alias_domain.active= true EOF cat - <<EOF >sql/pgsql_virtual_alias_maps.cf user=postfix password = $PGPW hosts = localhost dbname = postfix query = Select goto From alias Where address='%s' and active ='1' EOF cat - <<EOF >sql/pgsql_virtual_domains_maps.cf user=postfix password = $PGPW hosts = localhost dbname = postfix query = Select domain from domain where domain='%s' and active='1' EOF cat - <<EOF >sql/pgsql_virtual_mailbox_limit_maps.cf user=postfix password = $PGPW hosts = localhost dbname = postfix query = Select quota from mailbox where username='%s' and active='1' EOF cat - <<EOF >sql/pgsql_virtual_mailbox_maps.cf user=postfix password = $PGPW hosts = localhost dbname = postfix query = Select maildir from mailbox where username='%s' and active=true EOF

Spam Filtering

Add the following line to /etc/postfix/main.cf

#content_filter = scan:[127.0.0.1]:10025                                                      

Relay for Authenticated Users

# TLS Stuff -- since we allow SASL with tls *only*, we have to set up TLS first                    

smtpd_tls_cert_file = /etc/lighttpd/server-bundle.pem                                              
smtpd_tls_key_file = /etc/lighttpd/server-bundle.pem                                               
smtpd_tls_CAfile = /etc/lighttpd/ca-crt.pem                                                        
smtpd_tls_security_level = may                                                                     
# Log info about the negotiated encryption levels                                                  
smtpd_tls_received_header = yes                                                                    
smtpd_tls_loglevel = 1                                                                             
                                                                                                  
                                                                                                  
# SASL - this allows senders to authenticiate themselves                                            
# This along with "premit_sasl_authenticated" in smtpd_recipient_restrictions above allows relaying
smtpd_sasl_type = dovecot                                                                          
smtpd_sasl_path = private/dovecot-auth.sock                                                        
smtpd_sasl_auth_enable = yes                                                                       
smtpd_sasl_authenticated_header = yes                                                              
smtpd_tls_auth_only = yes