Thanks for reading but i have solved most of my problems right now.
I can create accounts using web-cyradm and send/recieve with squirrelmail without problems.
My problem is the use of mail-programs (like M$ Outlook).
Then it gets relay access denied.
I must admit that i dont understand the relay-function. I have no idea how to configure it, right now i have "relayhost = ".
I need the server to be as safe as it can be so that no one can spam through it. But what can i use as a relayhost?
thanks in advance
btw: im using postfix,cyrus, saslauthd for authentication and mysql for database