Today, I got the answer from a IT company whom I made a bid to take care of their Linux servers. This was (part of) their reply:
First and foremost, thank you for the substantial and impressing reaction on our request for a proposal. If we had any doubts about your knowledge about this subject, those are most definitely gone now. At the same time, this is also our motivation in deciding not to make use of this proposal: your level of quality is far too much in the light of the level of dependance we have on these machines.
Man, that guy sure can reject! If I had more rejections like this one, I wouldn't mind them so much! ;-)