What has to be made differently, to use Dovecot instead of Courier in this particular setup? From what I have read so far, Dovecot seems to be far more tempting than Courier nowadays, and I guess it should not be that difficult to replace Courier with Dovecot (which is what even Christoph Haas in his outdated tutorial for Debian Etch). On my search I only found an up-to-date tutorial on exchanging Courier with Dovecot for an ispCP Omega setup. As I am new to this, it is very time-consuming to gather all the necessary info from different sources. So maybe someone (Falko?) can point out, what exactly has to be done, to go "Virtual Users And Domains With Postfix, Courier, MySQL And SquirrelMail (Ubuntu 9.04)" with Dovecot instead of Courier.