Once apon a time I had a really good Exim4 configuration. It was more
arse than class, and I wouldn't have a clue how I did it, and where I
got the bits from that went into it. But I want to try and redo it.

Trouble is that last time I did try to do anything with my Exim4
configs, I was wondering where my system messages had dissapeared to,
when I got a polite email from some other customer on my ISP.

So, I'm wondering, how to safely test a new configuration before putting
it into action, and what corner cases to watch out for...


Fredderic