AMS routing cycle

I read the article on installing Postfix but it appears I am having troubles with AMS (under 10.2) already and documentation is scarce. We have a domain for which we want to receive mail to local users on an OSX Server system. I have set up the usernames to receive mail but it is not entirely clear how, for example, the 'local hosts names' in the setup utility interact with sendmail etc - is this the correct place to define virtual hosts? Anyway, the result is, that in my near default configuration, I am getting routing cycles when I try to send mail. [quote:72e345f06f]Could not deliver message (ID=172). Local account 'awtimmering@jnwb.nl' contains a routing cycle.[/quote:72e345f06f] I found some message on the net saying other people had this problem as well but couldn't find the solution. Could someone help me out? Regards, Ad Timmering