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'; $CONF['new_quota_table'] = 'YES';
Go to http://host.example.com/postfixadmin/setup.php
Create the password hash, add it to the config.inc.php file
Go back to http://host.example.com/postfixadmin/setup.php
Create superadmin, create a mail domain or other, as desired.
Install Postfix
Create a user for the virtual mail delivery, and get its uid/gid (you'll need the numeric uid/gid for postfix)
adduser vmail -H -D -s /bin/false grep vmail /etc/passwd
(In examples below, we use 1006/1006 for the uid/gid)
Create the mail directory, and assign vmail as the owner
mkdir -p /var/mail/domains chown -R vmail:vmail /var/mail/domains
Install postfix
apk add acf-postfix postfix-pgsql
Edit the /etc/postfix/main.cf file Here's an example:
myhostname=host.example.com
mydomain=example.com
mydestination = localhost.$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. Change PGPW to the password for the postfix user of the postfix SQL database.
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_maps.cf
user=postfix
password = $PGPW
hosts = localhost
dbname = postfix
query = Select maildir from mailbox where username='%s' and active=true
EOF
chown -R postfix:postfix sql chmod 640 sql/*
At this point you should be able to start up postfix
newaliases # so postfix is happy... /etc/init.d/postfix start rc-service add postfix
Create a domain in PostfixAdmin and test
create a domain for the local box (e.g. example.com) Create the alias accounts
From the machine, send a test message:
sendmail -t root@example.com subject: test . ^d
In /var/log/mail.log (or /var/log/messages, if you still have busybox syslogd running) you should see the message queued. The message should be in /var/mail/domains/example.com/root/new
Install Dovecot
Dovecot is the POP3/IMAP server to retrieve mail.
As before, we install dovecot:
apk add acf-dovecot dovecot-pgsql
edit /etc/dovecot.conf
# Select only the protocols you wish to support - all are listed in the next line protocols = imap imaps pop pop3s log_path = /var/log/dovecot.log info_log_path = /var/log/dovecot-info.log disable_plaintext_auth = no
# Authenticated IMAP
ssl = yes
ssl_cert_file = /etc/lighttpd/server-bundle.pem
ssl_key_file = /etc/lighttpd/server-bundle.pem
auth_verbose = yes
auth_debug = no
mail_location = maildir:/var/mail/domains/%d/%n
auth default {
mechanisms = plain
passdb sql {
args = /etc/dovecot/dovecot-sql.conf
}
userdb static {
args = uid=1006 gid=1006 home=/var/mail/domains/%d/%n
}
We need a certificate for SSL/TLS authentication, so in the example above, we use the lighttpd cert. That way when the cert is renewed/replaced, Dovecot will have access to the new cert as well.
Create the /etc/dovecot/dovecot-sql.conf file:
driver = pgsql connect = host=localhost dbname=postfix user=postfix password=******** password_query = select username,password from mailbox where local_part = '%n' and domain = '%d' default_pass_scheme = MD5-CRYPT
Again, change the password above to your postfix user password, and protect the file from prying eyes:
chown root:root /etc/dovecot/dovecot-sql.conf chmod 600 /etc/dovecot/dovecot-sql.conf
Start dovecot
/etc/init.d/dovecot start rc-update add dovecot
Testing
Make sure your firewall allows in ports 25(SMTP) 110 (POP3), 995 (POP3S), 143(IMAP), 993(IMAPS), or whatever subset you support.
At this point, you should be able to:
* Create a new domain and add users with PostfixAdmin * Send mail to those users via SMTP to port 25 * Retrieve mail using the user's full email and password (e.g. username: user@example.com password: ChangeM
Value Add Stuff
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
/etc/dovecot/dovecot.conf
# this is for postfix SASL (authenticated users can relay through us)
socket listen {
client {
path = /var/spool/postfix/private/dovecot-auth.sock
mode = 0660
user = postfix
group = postfix
}
}
}
== log rotation ==