http://korma.wmflabs.org/browser/mls.html states that Andre Klapper is the most active mailing list participant in the last 365 days with 1066 messages, and the 2nd most active all-time participant.
I have a hard time believing that.
My guess was that these high numbers were due to emails triggered by Andre Klapper's activity in issue trackers (Phabricator; Bugzilla until Nov 2014) but looking at the currently indexed lists at https://github.com/Bitergia/mediawiki-repositories/blob/master/mlstats_mailing_lists.conf I do not see any of the four "bug notification only" mailing lists:
* wikibugs-l became inactive in Nov 2014 due to the switch from Bugzilla to Phabricator
* pywikibot-bugs not listed (but see below)
* wikidata-bugs not listed
* tools-nlwikibots not listed and very low traffic.
Looking at http://korma.wmflabs.org/browser/people.html?id=360cfd7aca56c90c4cc6ad653bb5b263db9b62f7 under "Mailing lists" it states that
* 1) Andre Klapper sent 764 emails in May 2015
* 2) Andre Klapper sent 1055 emails in Dec 2014.
Looking at the previous version at https://github.com/Bitergia/mediawiki-repositories/commit/7a201aea22b00e664876b8f093da23abb131efe7 I see that http://lists.wikimedia.org/pipermail/pywikipedia-bugs was indexed until Nov 2015 which is the only mailing list receiving bugmail from Phabricator.
My assumption is not covered by
* 1) https://lists.wikimedia.org/pipermail/pywikibot-bugs/2015-May/thread.html which only lists 5 emails by "aklapper"
* 2) https://lists.wikimedia.org/pipermail/pywikibot-bugs/2014-December/thread.html which only lists 7 emails.
* 2) https://lists.wikimedia.org/pipermail/pywikibot-bugs/2014-November/thread.html lists 638 Phabricator emails by aklapper, triggered by fixing T1282. If this was related, stats would be off by one month, but I could not find similar Phabricator mass-editing activity on Pywikibot tasks in the months around May 2015.
1) And going to my mail account's "Sent" folder (which obviously also has any private, non-mailing list emails in there), I seem to have sent less than 100 emails in May 2015 (I was on holidays half of that month).
So I assume the numbers in korma are incorrect, and I'd welcome some investigation.