pflogsumm is a great tool to generate a (daily) report on Postfix logs. SRS-rewrites invalidate the From-addresses, but the log files can be preprocessed as a workaround.
More information on pflogsumm can be found in this man-page
If you configured SRS on your Postfix mailserver, From-addresses get rewritten to
SRS0=HHH=TT=booking.com=mailing@foxinnovations.be
To allow correct reporting on From-addresses and From-domains by pflogsumm, you can replace the SRS-addresses by there original counterparts by running this script:
cat /var/log/mail.log.1 /var/log/mail.log \
| sed 's/<SRS0=[^=]*=[^=]*=\([^=]*\)=\([^@]*\)@.*>/<\2@\1>/g' \
| sed 's/<SRS1=[^=]*=[^=]*==[^=]*=[^=]*=\([^=]*\)=\([^@]*\)@.*>/<\2@\1>/g'
For example, to mail a report about yesterday, this script can be run:
cat /var/log/mail.log.1 /var/log/mail.log \
| sed 's/<SRS0=[^=]*=[^=]*=\([^=]*\)=\([^@]*\)@.*>/<\2@\1>/g' \
| sed 's/<SRS1=[^=]*=[^=]*==[^=]*=[^=]*=\([^=]*\)=\([^@]*\)@.*>/<\2@\1>/g' \
| /usr/sbin/pflogsumm -d yesterday > /tmp/mail 2>&1
cat /tmp/mail | mail -aFrom:myserver@example.com -s "[Mon] Mail stats" me@example.com
You can call this script from your crontab, e.g. every day, a few minutes after midnight.