The page postfix.org/OVERVIEW.html presents and explains the individual parts of Postfix and their functions: services, queues, etc. Although some of the relationships are outlined in a schematic ASCII overview, there is no overall overview. To facilitate understanding of Postfix and make it easier to get started with the topic, we have created this overview as far as possible based on the information on the page:
The graphic is also available as a PDF.
However, it should be noted that the diagram does not take into account all connections and relationships. For example, the flush process is greatly simplified, as communication with smtpd and qmgr is not shown. The integration of policyd’s, such as for greylisting, is also missing.
The sources in ODG format are stored in a Github repository – unfortunately, however, the paths in the ODG file do not seem to be particularly stable. Many thanks again to Patrick Ben Koetter for the original idea to create such an image!
This article was originally written by Roland Wolters.