I'm getting closer, but...
Have just posted ths: http://www.howtoforge.com/forums/sho...156#post295156
regarding this reinstallation. I'm not sure about what to do with the "do-release-upgrade"!?! Is it more right to do this now or after the installation of ISPConfig3 CP. Will it make any difference.
Well, I lost some courage durin these reinstallations. Maybe because of the "long nights" without any sleep or maybe just because I would like to make it the right way
And, I am not sure about mailman either, because, I'm not quite sure if I will need it or exactly what it does - but due to the tutorial it is recommended that you install it before the ISPConfig3 CP!