Comment # 1 on bug 1069470 from Freek de Kruijf

type=AVC msg=audit(1511434154.026:50): apparmor="DENIED" operation="mknod"
profile="/usr/sbin/nscd" name="/var/lib/nscd/passwd" pid=1068 comm="nscd"
requested_mask="c" denied_mask="c" fsuid=0 ouid=0
type=AVC msg=audit(1511434154.026:51): apparmor="DENIED" operation="mknod"
profile="/usr/sbin/nscd" name="/var/lib/nscd/group" pid=1068 comm="nscd"
requested_mask="c" denied_mask="c" fsuid=0 ouid=0
type=AVC msg=audit(1511434154.026:52): apparmor="DENIED" operation="mknod"
profile="/usr/sbin/nscd" name="/var/lib/nscd/services" pid=1068 comm="nscd"
requested_mask="c" denied_mask="c" fsuid=0 ouid=0
type=AVC msg=audit(1511434154.026:53): apparmor="DENIED" operation="mknod" 
After a reboot and making a connection with kmail to dovecot on the same
system, the following messages appear in /var/log/audit/audit.log :

profile="/usr/sbin/nscd" name="/var/lib/nscd/netgroup" pid=1068 comm="nscd"
requested_mask="c" denied_mask="c" fsuid=0 ouid=0
type=AVC msg=audit(1511435158.225:52): apparmor="DENIED" operation="mknod"
profile="/usr/sbin/nscd" name="/var/lib/nscd/passwd" pid=1112 comm="nscd"
requested_mask="c" denied_mask="c" fsuid=0 ouid=0
type=AVC msg=audit(1511435158.225:53): apparmor="DENIED" operation="mknod"
profile="/usr/sbin/nscd" name="/var/lib/nscd/group" pid=1112 comm="nscd"
requested_mask="c" denied_mask="c" fsuid=0 ouid=0
type=AVC msg=audit(1511435158.225:54): apparmor="DENIED" operation="mknod"
profile="/usr/sbin/nscd" name="/var/lib/nscd/services" pid=1112 comm="nscd"
requested_mask="c" denied_mask="c" fsuid=0 ouid=0
type=AVC msg=audit(1511435158.225:55): apparmor="DENIED" operation="mknod"
profile="/usr/sbin/nscd" name="/var/lib/nscd/netgroup" pid=1112 comm="nscd"
requested_mask="c" denied_mask="c" fsuid=0 ouid=0
type=AVC msg=audit(1511435306.574:92): apparmor="DENIED" operation="capable"
profile="/usr/lib/dovecot/auth" pid=3110 comm="auth" capability=2 
capname="dac_read_search"
type=AVC msg=audit(1511435306.574:93): apparmor="DENIED" operation="capable"
profile="/usr/lib/dovecot/auth" pid=3110 comm="auth" capability=1 
capname="dac_override"
type=AVC msg=audit(1511435306.882:96): apparmor="DENIED" operation="capable"
profile="/usr/lib/dovecot/auth" pid=3110 comm="auth" capability=2 
capname="dac_read_search"
type=AVC msg=audit(1511435306.882:97): apparmor="DENIED" operation="capable"
profile="/usr/lib/dovecot/auth" pid=3110 comm="auth" capability=1 
capname="dac_override"

Now I still have access to the email messages via dovecot in contrary to
yesterday when I made the first bug report, when I could not access the
messages.