I have this user who have a lot of cron jobs and I expected it to log stderr in its /var/mail/user. Sample below cron entry is working as expected in a different server.
* 30 * * * * /usr/local/bin/scripts/test.sh > /dev/null 2>&1
I've compared postfix/main.cf on both servers and cannot find anything different. Is there something else I need to check?