This file lists modified examples from
http://www.howtoforge.com/virtual-users-domains-postfix-courier-mysql-squirrelmail-debian-lenny-p2
to be usable with the postfixadmin default DB layout. Written 2010-04-28.

/etc/postfix/

mysql-virt-domains.cf:
user = mail_admin
password = secretpassword
dbname = virtmail
query = SELECT domain AS virtual FROM domain WHERE domain='%s'
hosts = 127.0.0.1

mysql-virt-email2email.cf:
user = mail_admin
password = secretpassword
dbname = virtmail
query = SELECT username FROM mailbox WHERE username='%s'
hosts = 127.0.0.1

mysql-virt-forwardings.cf:
user = mail_admin
password = secretpassword
dbname = virtmail
query = SELECT goto FROM alias WHERE address='%s'
hosts = 127.0.0.1

mysql-virt-mailboxes.cf:
user = mail_admin
password = secretpassword
dbname = virtmail
query = SELECT CONCAT(SUBSTRING_INDEX(username,'@',-1),'/',SUBSTRING_INDEX(username,'@',1),'/') FROM mailbox WHERE username='%s'
hosts = 127.0.0.1

sasl/smtpd.conf:
pwcheck_method: saslauthd
mech_list: PLAIN LOGIN
allow_plaintext: true
auxprop_plugin: mysql
sql_hostnames: 127.0.0.1
sql_user: mail_admin
sql_passwd: secrectpassword
sql_database: virtmail
sql_select: SELECT password FROM mailbox WHERE username = '%u'


/etc/courier/

authmysqlrc:
MYSQL_SERVER localhost
MYSQL_USERNAME mail_admin
MYSQL_PASSWORD secretpassword
MYSQL_PORT 0
MYSQL_DATABASE virtmail
MYSQL_USER_TABLE mailbox
MYSQL_CRYPT_PWFIELD password
MYSQL_UID_FIELD 800
MYSQL_GID_FIELD 800
MYSQL_LOGIN_FIELD username
MYSQL_HOME_FIELD "/var/spool/vmail"
MYSQL_MAILDIR_FIELD CONCAT(SUBSTRING_INDEX(username,'@',-1),'/',SUBSTRING_INDEX(username,'@',1),'/')
#Note to myself: It's possible to avoid the concat construct, take a closer look at the mailbox table

/etc/pam.d/smtp:
auth    required   pam_mysql.so user=mail_admin passwd=secretpassword host=127.0.0.1 db=virtmail table=mailbox usercolumn=username passwdcolumn=password crypt=1
account sufficient pam_mysql.so user=mail_admin passwd=secretpassword host=127.0.0.1 db=virtmail table=mailbox usercolumn=username passwdcolumn=password crypt=1