I've had today a task at work to monitor a postfix mail send and received emails (MAIL FROM / RPCT TO) and get out a simple statistics on what kind of emails are coming and going out from the Postfix SMTP on a server?
Below is shortly explained how I did it plus you will learn how you can use something more advanced to get server mail count, delivery status, errors etc. daily.
1. Using a simple script to process /var/log/messages
For that I made a small script to do the trick, the script simply checks mail delivery logged information from /var/log/maillog process a bit sort and logs in a separate log daily.
#!/bin/sh
# Process /var/log/maillog extract from= and to= mails sort
# And log mails to $LOGF
# Author Georgi Georgiev 14.07.2020DATE_FORM=$(date +'%m_%d_%y_%H_%M_%S_%h_%m');
LOG='/home/gge/mail_from_to-mails';
LOGF="$LOG.$DATE_FORM.log";
CUR_DATE=$(date +'%m_%d_%y_%T');
echo "Processing /var/log/maillog";
echo "Processing /var/log/maillog" > $LOGF;
echo >>$LOGF
echo "!!! $CUR_DATE # Sent MAIL FROM: addresses: !!!" >> $LOGF;
grep -E 'from=' /var/log/maillog|sed -e 's#=# #g'|awk '{ print $8 }'|sed -e 's#<# #g' -e 's#># #g' -e 's#\,##'|sort -rn|uniq >> $LOGF;echo "!!! $CUR_DATE # Receive RCPT TO: addresses !!!" >>$LOGF;
grep -E 'to=' /var/log/maillog|sed -e 's#=# #g'|awk '{ print $8 }'|sed -e 's#<# #g' -e 's#># #g' -e 's#\,##'|sort -rn|uniq >> $LOGF;
You can get a copy of the mail_from_to_collect_mails_postfix.sh script here.
I've set the script to run via a crond scheduled job once early in the mornthing and I'll leave it like that for 5 days or so to get a good idea on what are the mailboxes that are receiving incoming mail.
The cron I've set to use is as follows:
# crontab -u root -l
05 03 * * * sh /home/gge/mail_from_to.sh >/dev/null 2>&1
This will be necessery later for a Email Server planned migration to relay its mail via another MTA host.
2. Getting More Robust Postifx Mail Statistics from logs
My little script is of course far from best solution to get postfix mail statistics from logs.
If you want something more professional and you need to have a daily report on what mails sent to mail server and mails sent from the MTA to give you information about the Email delivery queue status, number of successful and failed emails from a mail sender / recipient and a whole bunch of useful info you can use something more advanced such as pflogsumm perl script to get daily / weekly monthly mail delivery statistics.
What can pflogsumm do for you ?
Pflogsumm is a log analyzer/summarizer for the Postfix MTA. It is
designed to provide an overview of Postfix activity, with just enough
detail to give the administrator a “heads up” for potential trouble
spots and fixing any SMTP and email related issues.
Pflogsumm generates summaries and, in some cases, detailed reports of
mail server traffic volumes rejected and bounced email and server
warnings, errors, and panics.
At the time of writting this article it is living on jimsun.linxnet.com just in case if pflogsumm.pl's official download location disappears at some time in future here is pflogsumm-1.1.3.tar.gz mirror stored on www.pc-freak.net
– Install pflogsumm
Use of pflogsumm is pretty straight forward, you download unarchive the script to some location such as /usr/local/bin/pflogsumm.pl add the script executable flag and you run it to create a Postfix Mail Log statistics report for you
wget http://jimsun.linxnet.com/downloads/pflogsumm-1.1.3.tar.gz -O /usr/local/src/pflogsumm-1.1.3.tar.gz
# mkdir -p /usr/local/src/
# cd /usr/local/src/
# tar -zxvf pflogsumm-1.1.3.tar.gz
# cd pflogsumm-1.1.3/# mv /usr/local/pflogsumm-1.1.3/pflogsumm.pl /usr/local/bin/pflogsumm
# chmod a+x /usr/local/bin/pflogsumm
That's all, assuming you have perl installed on the system with some standard modules, we're now good to go:
To give it a test report to the command line:
# /usr/local/bin/pflogsumm -d today /var/log/maillog
To generate mail server use report and launch to some email of choice do:
# /usr/local/bin/pflogsumm -d today /var/log/maillog | mail -s Mailstats your-mail@your-domain.com
To make pflogsumm report everyday various interesting stuff such as (message deferrals, message bounce, details, smtp delivery failures, fatal errors, recipients by message size etc. add some cronjob like below to the server:
# /usr/sbin/pflogsumm -d yesterday /var/log/maillog | mail -s Mailstats | mail -s Mailstats your-mail@your-domain.com
If you need a GUI graphical mail monitoring in a Web Browser, you will need to install a webserver with a perl / cgi support, RRDTools and MailGraph.
