lmtp deliver failed

[Dmitry P. Schegolev]

Try to test cyrus-2.2.3 imapd + postfix, using lmtp socket.
System is Gentoo. 

The following error occured:

Jan 16 14:19:11 kenwood postfix/smtpd[11631]: connect from 
dgap-gw.mipt.ru[194.85.81.130]
Jan 16 14:19:11 kenwood postfix/smtpd[11631]: 4A0551070F2: 
client=dgap-gw.mipt.ru[194.85.81.130]
Jan 16 14:19:11 kenwood postfix/cleanup[11632]: 4A0551070F2: 
message-id=<200401161419.02271.dmitry at anexo.ru>
Jan 16 14:19:11 kenwood postfix/qmgr[11542]: 4A0551070F2: 
from=<dmitry at anexo.ru>, size=883, nrcpt=1 (queue active)
Jan 16 14:19:11 kenwood postfix/smtpd[11631]: disconnect from 
dgap-gw.mipt.ru[194.85.81.130]
Jan 16 14:19:11 kenwood master[11636]: about to exec /usr/cyrus/bin/lmtpd
Jan 16 14:19:11 kenwood lmtpunix[11636]: executed
Jan 16 14:19:11 kenwood lmtpunix[11636]: accepted connection
Jan 16 14:19:11 kenwood lmtpunix[11636]: lmtp connection preauth'd as postman
Jan 16 14:19:11 kenwood master[1689]: process 11636 exited, signaled to death 
by 11
Jan 16 14:19:11 kenwood master[1689]: service lmtpunix pid 11636 in BUSY 
state: terminated abnormally
Jan 16 14:19:11 kenwood postfix/lmtp[11635]: 4A0551070F2: 
to=<test at kenwood.dgap.mipt.ru>, relay=/var/imap/socket/lmtp[/var/imap/socket/
lmtp], delay=0, status=deferred (lost connection with /var/imap/socket/lmtp[/
var/imap/socket/lmtp] while sending MAIL FROM)

Why it so? What does it mean "signaled to death by 11"?