Cyrus, Fetchmail and Postfix [CentOS]

[d3m0nic]

Hello,

I installed cyrus-imapd, cyrus-imapd-devel, cyrus-imapd-utils, cyrus-sasl-devel, cyrus-sasl-gssapi, cyrus-sasl-plain. I've tested the Cyrus Server by:

[root@server1 ~]# imtest
WARNING: no hostname supplied, assuming localhost

S: * OK server1.mydomain.tld Cyrus IMAP4 v2.2.12-Invoca-RPM-2.2.12-3.RHEL4.1 
server ready
C: C01 CAPABILITY
S: * CAPABILITY IMAP4 IMAP4rev1 ACL QUOTA LITERAL+ MAILBOX-REFERRALS 
NAMESPACE UIDPLUS ID NO_ATOMIC_RENAME UNSELECT CHILDREN MULTIAPPEND 
BINARY SORT THREAD=ORDEREDSUBJECT THREAD=REFERENCES ANNOTATEMORE 
IDLE STARTTLS LISTEXT LIST-SUBSCRIBED X-NETSCAPE
S: C01 OK Completed
Please enter your password:

[root@server1 ~]# service cyrus-imapd status
cyrus-master (pid 2558) is running...

Postfix is running too:

[root@server1 ssl]# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 server1.mydomain.tld ESMTP Postfix
ehlo localhost
250-server1.mydomain.tld
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250 8BITMIME
quit
221 Bye
Connection closed by foreign host.[root@server1 ssl]#

So, i'm very happy about that... but what NOW!

How do i use these daemons? Can i send email to e.g. johnny@mydomain.tld or do i first have to create a new user with its own directory in /home. I keep getting "premission denied" in cyradm:

[root@server1 ~]# cyradm localhost
IMAP Password:
server1.mydomain.tld> createmailbox user john
createmailbox: Permission denied
server1.mydomain.tld>

I seem to have some trouble grasping what the hell Cyrus, Fetchmail and Postfix is doing and how i can use this. I tried connecting with Thunderbird to ... whatever was out there, but this did nothing. no surprise there, sins i did not configure an account... you see, i don't know what to do next. I'd like to create my own emailaccount on www.mydomain.tld to test it, before i start installing ISPConfig. I have to know how this stuff works, because i want to know... i NEED to know.

I've done most part of Perfect Setup Fedora Core 4... except where the distro's slightly differ from eachother. I've read a lot of Cyrus docs and FAQ, but i couldn't find any good moron-proof tut, telling not only how to config the daemon but how to create accounts which can be used in a mailclient like Mozilla TB or Outlook Ex.

Many thanks