Strange thing is.
I installed new server and configured server (The Perfect Server). I think it configures Dovecot and Sieve. After that I migrated from the old server, it is configured like Courier and Maildrop. I also copied the ispconfig database I guess it changed the setting in ispconfig back to courier and maildrop. Because when I open the new server and go to System > Server Config > Mail it sais:
POP3/IMAP Daemon: Courier
Mailfilter Syntax: Maildrop
Should I change it to Dovecot and Sieve? Because I think everything works fine...?