PostfixCompleteVirtualMailSystemHowto - Community Ubuntu Documentation
Postfix Configuration Parameters main.cf
Postfix Virtual Domain Hosting Howto
http://www.postcastserver.com/help/Blocking_Open_Relays.aspx
http://www.no-ip.com/services/managed_mail/inbound_port_25_unblock.html
http://www.checkor.com/
Spam in Postfix
Filtering email with postfix and procmail
Reading message information with PHP
Authenticated SMTP
Dovecot Pigeonhole Sieve support

http://wiki.cyprix.com.au/wiki/CyprixMailHowto

http://www.emailaddressmanager.com/tips/mail-servers.html

http://www.postfix.org/postconf.5.htm
http://flurdy.com/docs/postfix/

SASL did not work and the following was removed from main.cf
Need to figure this out and put it back.

#SMTP Authentication
smtpd_recipient_restrictions = reject_unauth_pipelining, permit_mynetworks, permit_sasl_authenticated, reject_non_fqdn_recipient, reject_unauth_destination, check_policy_service
# modify the existing smtpd_sender_restrictions
smtpd_sender_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_non_fqdn_sender, reject_unknown_sender_domain, reject_unauth_pipelining, permit
# then add these
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_sasl_path = /etc/postfix/sasl:/usr/lib/sasl2
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain =

This might be useful in debugging!

To restart a bunch all at once!

etc/init.d/courier-authdaemon restart ; /etc/init.d/courier-imap restart; /etc/init.d/postfix restart