You have mail in /var/spool/mail/root
[root@kolab ~]# mail
Heirloom Mail version 12.4 7/29/08.  Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N  1 Anacron               Fri Mar 11 20:42  24/892   "Anacron job 'cron.daily' on kolab.example.org"
& 
Message  1:
From root@kolab.example.org  Fri Mar 11 20:42:52 2016
Return-Path: <root@kolab.example.org>
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From: Anacron <root@kolab.example.org>
To: root@kolab.example.org
Content-Type: text/plain; charset="ANSI_X3.4-1968"
Subject: Anacron job 'cron.daily' on kolab.example.org
Date: Fri, 11 Mar 2016 20:42:50 +0100 (CET)
Status: R

/etc/cron.daily/logrotate:

error: pykolab:3 unknown option 'su' -- ignoring line
error: pykolab:3 unexpected text

& q
Held 1 message in /var/spool/mail/root
[root@kolab ~]# cat /etc/logrotate.d/pykolab 
/var/log/kolab/pykolab.log {
  create 0660 kolab kolab-n
  su kolab kolab-n
  compress
  missingok
  notifempty
  rotate 52
  weekly
}