Rating: 

Book is fine, but I found a lot of theory but not many examples usefull for typical configuration (f.e. for home user, for firms). I must ellaborate myself, but it's a great waste of my time. Mailing list is a big help, but I recommend for futher development to focus on documentation, which is "not good enough". F.e. there is a missing search in www.exim.org for documentation. It's a work for one day for advanced web developer. I can only search in mailing list or use google instead.

But, at the end thumb up for Philip Hazel for his Exim and for all us using open source software...

Milan