Why "Hellcore Mailer" is free?
Good question. When I started developing it, I quickly found out that my program isn't that bad and is worth even 10$. But then I was astonished by a simple fact - how much cash other developers want for their software. I was accustomed to fact that you pay for quality - but most of commercial/shareware programs only had a lot of useless features and serious bugs coming from wrong assumptions (making them useless for - for example - polish user or owner of low-end machine). Besides, I share the David Harris (creator of a great Pegasus Mail application) opinion - freedom of speech is worth nothing if you have to pay for it.
This way, Hellcore Mailer has most of the other mail/news readers features and is far cheaper - free. Many users just because of this use it!