In the /usr/local/sbin/postfix_report.sh script it would probably be more efficient to use: zcat -f /var/log/mail.log.0.gz | pflogsumm | formail -c ..... instead of: gunzip /var/log/mail.log.0.gz pflogsumm /var/log/mail.log.0 | formail -c ..... gzip /var/log/mail.log.0