I get "Status Checks Change Notice" every day caused by dovecot restart

Every morning at 6:27 AM I’ve got a “Status Checks Change Notice” email with the following content:

System -- Previously:
=====================
✖  Dovecot LMTP LDA is not running ([Errno 111] Connection refused; 
   port 10026).
✖  Sieve (dovecot) is not running ([Errno 111] Connection refused; 
   port 4190).
✖  IMAPS (dovecot) is not running ([Errno 111] Connection refused; 
   port 993).

System -- Currently:
====================
✓  All system services are running.
Aug  1 06:25:20 box dovecot: imap: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill) 
Aug  1 06:25:20 box dovecot: imap: Server shutting down. in=701 out=6727 
Aug  1 06:25:20 box dovecot: imap: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill) 
Aug  1 06:25:20 box dovecot: imap: Server shutting down. in=179 out=1473 
Aug  1 06:25:20 box dovecot: imap: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill) 
Aug  1 06:25:20 box dovecot: imap: Server shutting down. in=124 out=1356 
Aug  1 06:25:20 box dovecot: imap-login: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill) 
Aug  1 06:25:20 box dovecot: imap-login: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill) 
Aug  1 06:25:20 box dovecot: log: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill) 
Aug  1 06:25:20 box dovecot: master: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill) 
Aug  1 06:25:21 box postfix/master[16511]: terminating on signal 15 
Aug  1 06:26:50 box postfix/master[5421]: daemon started -- version 2.11.0, configuration /etc/postfix 
Aug  1 06:26:50 box postfix/tlsmgr[5432]: open smtp TLS cache btree:/var/lib/postfix/smtp_scache 
Aug  1 06:26:50 box postfix/tlsmgr[5432]: tlsmgr_cache_run_event: start TLS smtp session cache cleanup 
Aug  1 06:26:50 box postfix/smtpd[5431]: connect from box.....
Aug  1 06:26:50 box postfix/smtpd[5431]: lost connection after CONNECT from box.... 
Aug  1 06:26:50 box postfix/smtpd[5431]: disconnect from box..
Aug  1 06:27:01 box dovecot: master: Dovecot v2.2.9 starting up (core dumps disabled) 
Aug  1 06:27:02 box dovecot: config: Warning: service auth { client_limit=1000 } is lower than required under max. load (5000) 
Aug  1 06:27:02 box dovecot: config: Warning: service anvil { client_limit=1000 } is lower than required under max. load (4003)

But I don’t find any config file that do a dovecot / postfix kill.

/etc/logrotate.d/rsyslog rotate the mail.* files, but do not kill, since that kill is every day, logrotate is not the cause:

/var/log/mail.info
/var/log/mail.warn
/var/log/mail.err
/var/log/mail.log
/var/log/daemon.log
/var/log/kern.log
/var/log/auth.log
/var/log/user.log
/var/log/lpr.log
/var/log/cron.log
/var/log/debug
/var/log/messages
{
        rotate 4
        weekly
        missingok
        notifempty
        compress
        delaycompress
        sharedscripts
        postrotate
                reload rsyslog >/dev/null 2>&1 || true
        endscript
}

I grep around for kill, hub, etc. in /etc/ but didn’t find any helpful hint.

Does somebody else got this good morning mail from miab?

Thanks.

Cheers

Chris

The last time I got those messages, my disk was full.

My disk is on 26% used. So that should be not the reason.