Here you will find some other resources available in the internet.
Some of the most interesting news groups are:
Maybe you also check out your country newsgroups e.g ch.comp.os.linux
Most newsgroups have their own FAQ that are designed to answer most of your questions, as the name Frequently Asked Questions indicate. Fresh versions should be posted regularly to the relevant newsgroups. If you cannot find it in your news spool you could go directly to the FAQ main archive FTP site. The WWW versions can be browsed at the FAQ main archive WWW site.
Send an mail to <majordomo at postfix.org> with the content (not subject):
Before writing to the list, check out the archive: http://www.deja.com/group/mailing.postfix.users
Send an mail to <majordomo at lists.andrew.cmu.edu> with the content (not subject):
Before writing to the list, check out the archive: http://asg.web.cmu.edu/archive/index.php?mailbox=archive.info-cyrus
Subscription can be done trough the webinterface http://www.web-cyradm.org/mailman/listinfo/web-cyradm
Before writing to the list, check out the archive for similar incidents: http://www.web-cyradm.org/pipermail/web-cyradm/
This are intended as the primary starting points to get the background information as well as show you how to solve a specific problem. Some relevant HOWTOs are Cyrus-IMAP and Apache-Compile-HOWTO. The main site for these is the LDP archive.
There a few other HOWTOs and freely available documentations outside of the TLDP.org
IBM recently released a new Redbook: BladeCenter, Linux, and Open Source: Blueprint for e-business on demand.Especially chapter 6 is interesting when looking for email solutions.
Usually distributions installs some documentation to your system. As a standard they are located in /usr/share/doc/packages
The SuSE rpms of Cyrus contains a lot a such documentation.
Postfix has some html-files in the source directory /usr/local/postfix-2.0.16/html
PAM comes also with lots of documentation in /usr/share/doc/packages/pam
The pam_mysql module has a README with the incredible size of 1670 bytes.
There are a huge number of informative web sites available. By their very nature they change quickly so do not be surprised if these links become quickly outdated.
A good starting point is of course the Linux Documentation Project home page, an information central for documentation, project pages and much more.
To get more deepened information about Postfix, then www.postfix.org would be the starting point.
Please let me know if you have any other leads that can be of interest.