Добрый день,

редко в логах проскакивают такие строки:
Sep 30 23:41:09 corp postfix/pipe[18720]: 70C82DC8001: to=<irina@moredomain.ru>, relay=spamassassin, delay=2.7, delays=2/0/0/0.63, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 14:11:47 corp postfix/pipe[27406]: F1F62DC87B0: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=180, delays=1/178/0/1.2, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 14:23:23 corp postfix/pipe[18905]: 52A8FDC9FEB: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=769, delays=0.22/767/0/2.3, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 18:38:55 corp postfix/pipe[950]: 06570DC86AB: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=208, delays=1.3/207/0/0.22, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 18:44:05 corp postfix/pipe[17672]: 30C4BDC8FA8: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=491, delays=0.33/489/0/1.6, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 18:48:46 corp postfix/pipe[23006]: 2BEEDDC97A7: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=748, delays=1.6/744/0/2, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 18:49:10 corp postfix/pipe[20533]: A25FBDC9860: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=770, delays=0.81/767/0/1.9, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 18:52:17 corp postfix/pipe[25655]: 2E3D1DC9D88: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=942, delays=3.2/937/0/1.5, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 18:56:32 corp postfix/pipe[1190]: 4FBF6DC8465: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=1089, delays=0.42/1088/0/0.68, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Oct  2 18:59:20 corp postfix/pipe[9059]: 0FFA7DCA855: to=<myaddr@mydomain.ru>, orig_to=<admin@aliasdomain.ru>, relay=spamassassin, delay=1244, delays=0.94/1241/0/2.2, dsn=5.3.0, status=bounced (Command died with signal 11: "/usr/bin/spamc")
Из-за чего такое может происходить?

[root@corp ~]# rpm -qa | grep postfix
postfix-2.4.5-2
postfix-pflogsumm-2.4.5-2
[root@corp ~]# cat /etc/redhat-release
CentOS release 5 (Final)
postfix собран из своей srpm'ки. Версия 100% ванильная, ничего в ней не менялось.

postconf -m
btree
cidr
environ
hash
ldap
mysql
nis
pcre
proxy
regexp
static
tcp
unix

P.S. наргузка генерилась с помощью smtp-source.
P.P.S. без исскуственной нагрузки такие сообщения в логе случаются пару-тройку раз в неделю.