> I've done it many times before manually and it takes around ten hours to do it.

This is exactly why I've been using Postfix (or, preferably, get Google or someone else to handle it for me).

Easy to install is a feature, and a pretty close cousin of the "shipping" feature.

DJBs software is interesting mostly from an academic perspective. In the real world, it's hard to justify using something else, when apt-get gets the job done in literally seconds.