Well then, at least this one I could solve:
In postfix's main.cf, configure mailbox_transport as:
And in cyrus' cyrus.conf, edit the SERVICES section this way:
Code:
lmtp cmd="lmtpd -a cyrus" listen="localhost:lmtp" prefork=0 maxchild=20
#lmtpunix cmd="lmtpd" listen="/var/run/cyrus/socket/lmtp" prefork=0 maxchild=20
For some reason things did not work if both delivery services were enabled. But I didn't have the time to figure out the reason.
Greet-O-Mente