[Evolution] editing keyboard shortcuts

[Herr Oswald <herr_oswald gmx de>]

evo 3.16.5
ubuntu 15.04

Again, I'm trying to customize some keyboard shortcuts.
Found this blog entry: 

https://major.io/2015/11/27/custom-keyboard-shortcuts-for-evolution-in-
gnome/

but - as my comment says - the strategy described (edit
~/.config/evolution/accels) does not work for me. This file seems to be
generated from another origin, but I could not find that.

Can somebody tell me which file I have to edit to actually make
alterations with keyboard shortcuts?

Cheers,
Wolf