Sumo Logic + Email Dashboard | Geek and I
www.geekandi.com/2015/06/30/sumo-logic-email-dashboard
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Postfix + Dovecot syslog logs fed into your into Sumo Logic collector. Parse it to display dashboards of meaningful information and graphs.