chkuser 2.0 patch design
The whole of chkuser code is contained within separated files:
contains base definitions for chkuser
contains all the code necessary for chkuser
contains all the settings necessary to customize chkuser behaviours
Link within qmail-smtpd is done editing only some hook lines within qmail-smtpd.c, and modifying some lines in Makefile and conf-cc.
Picture of the structure
Following a semplified flow regarding chkuser design.