If you are utilizing Postfix and hosting virtual domains it’s likely you will want an overview of inbound and outbound email activity pre domain.

This sort of statistical information can be of huge benefit when running your own server, especially if you need to get an idea of where you bandwidth consumption is going.

Linking Awstats to Postfix

You can achieve this by using AWStats, but first you must run a few scripts in order to present the log file in a format that AWStats can work with. If you are using Amavis and/or Spamassassin, you will notice additional lines similar to these appear due to re-injection:

Apr 14 19:47:58 mailserver amavis[23740]: (23740-02) FWD via SMTP:  -> , 250 2.6.0 Ok, id=23740-02, from MTA([127.0.0.1]:10025): 250 Ok: queued as DAB321264FE
Apr 14 19:47:58 mailserver amavis[23740]: (23740-02) Passed CLEAN, [192.168.0.10] [192.168.0.10]  -> , Message-ID: <49E4D9FA.4020100@receiverdomain.com>, mail_id: J9-AzDhzWfe0, Hits: -, 160 ms

In order to avoid this, you must use prepflog to process the mail log before it is passed to pflogsumm or AWStats. This script will disregard the lines relating to the re-injection of messages into Postfix.

Once this is completed you will need to use maillogconvert. This is a mail log preprocessor that converts a mail log file (from postfix, sendmail or qmail servers) into a human readable format. The output format is also ready to be used by a log analyzer, like AWStats. The maillogconvert script is provided in the AWStats tools directory.

So let’s look at the configuration. Prepflog documentation says to set the following in the AWStats configuration file:

LogFile="/usr/local/bin/prepflog.pl < /var/log/mail | perl /usr/local/awstats/tools/maillogconvert.pl standard |"

However, we wish to only grab mail from one domain so I altered the setting to this:

LogFile="cat /var/log/mail.log | /etc/awstats/prepflog.pl | perl /etc/awstats/maillogconvert.pl standard | grep interestingdomain.com |"

After the log is striped of unnecessary re-injection entries, the specific domain is grepped, it is then pushed to maillogconvert.pl which outputs a friendly format as follows:

2009-04-14 20:38:03 sender@senderdomain.com receiver@receiverdomain.com 192.168.0.10 - SMTP - xxx ?

You must ensure that the AWStats configuration file is set-up to parse mail logs. I followed the formatting suggested by the AWStats documentation. Your configuration file awstats.mail.interestingdomain.com.conf will now look similar to this:

LogFile="cat /var/log/mail.log | /etc/awstats/prepflog.pl | perl /etc/awstats/maillogconvert.pl standard | grep interestingdomain.com |"
LogType=M
LogFormat="%time2 %email %email_r %host %host_r %method %url %code %bytesd"
LogSeparator=" "
SiteDomain="interestingdomain.com"
HostAliases="interestingdomain.com"
LogType=M
LevelForBrowsersDetection=0
LevelForOSDetection=0
LevelForRefererAnalyze=0
LevelForRobotsDetection=0
LevelForWormsDetection=0
LevelForSearchEnginesDetection=0
LevelForFileTypesDetection=0
ShowMenu=1
ShowSummary=HB
ShowMonthStats=HB
ShowDaysOfMonthStats=HB
ShowDaysOfWeekStats=HB
ShowHoursStats=HB
ShowDomainsStats=0
ShowHostsStats=HBL
ShowAuthenticatedUsers=0
ShowRobotsStats=0
ShowEMailSenders=HBML
ShowEMailReceivers=HBML
ShowSessionsStats=0
ShowPagesStats=0
ShowFileTypesStats=0
ShowFileSizesStats=0
ShowBrowsersStats=0
ShowOSStats=0
ShowOriginStats=0
ShowKeyphrasesStats=0
ShowKeywordsStats=0
ShowMiscStats=0
ShowHTTPErrorsStats=0
ShowSMTPErrorsStats=1

It is important to remember that you will need to set up a crontab entry to process the mail log. Your crontab entry should look similar to this:

/usr/bin/perl /usr/lib/cgi-bin/awstats.pl -update -config=mail.interestingdomain.com

Finally, below is my configuration for Apache 2:

###### AWSTATS ######
Alias /awstatsclasses "/usr/share/awstats/lib/"
Alias /awstats-icon/ "/usr/share/awstats/icon/"
Alias /awstatscss "/usr/share/doc/awstats/examples/css"
ScriptAlias /awstats/ /usr/lib/cgi-bin/
Options ExecCGI -MultiViews +SymLinksIfOwnerMatch

Now you will see a tidy graphical view of all mail traffic for your virtual domains using AWStats. If you have any questions or comments on how you go about generating stats, please fill in the comment form below.