grep 5001 /etc/passwd
getmail:x:5001:5001::/etc/getmail:/bin/bash

crontab -u getmail -e

*/5 * * * * /usr/local/bin/run-getmail.sh > /dev/null 2>> /var/log/ispconfig/cron.log

Error Msg

Return-Path: <[email protected]>
Received: by x.x.x.x (Postfix, from userid 5001)
    id A0F4161D61; Fri, 31 Oct 2014 02:35:01 +0800 (HKT)
From: [email protected] (Cron Daemon)
To: [email protected]
Subject: Cron <getmail@ispconfig> /usr/local/bin/run-getmail.sh > /dev/null 2>> /var/log/ispconfig/cron.log
Content-Type: text/plain; charset=UTF-8
Auto-Submitted: auto-generated
X-Cron-Env: <LANG=en_US.UTF-8>
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <HOME=/etc/getmail>
X-Cron-Env: <PATH=/usr/bin:/bin>
X-Cron-Env: <LOGNAME=getmail>
X-Cron-Env: <USER=getmail>
Message-Id: <[email protected]>
Date: Fri, 31 Oct 2014 02:35:01 +0800 (HKT)

/bin/sh: /var/log/ispconfig/cron.log: Permission denied