As below:
imap cmd="imapd -U 30" listen="localhost:imap" prefork=0 maxchild=100
imap cmd="imapd -U 30" listen="localhost:imap" prefork=0 maxchild=100
imaps cmd="imapd -s -U 30" listen="imaps" prefork=0 maxchild=100
pop3 cmd="pop3d -U 30" listen="localhost:pop3" prefork=0 maxchild=50
pop3s cmd="pop3d -s -U 30" listen="pop3s" prefork=0 maxchild=50
lmtpunix cmd="lmtpd" listen="/var/run/cyrus/socket/lmtp" prefork=0 maxchild=20
sieve cmd="timsieved" listen="localhost:sieve" prefork=0 maxchild=100