Dan has stated the situation very well. To that I would add that this is the General forum. Questions about creating CGI applications and mucking about with qmail are probably better posed in the Experienced forum, or on the devinfo mailing list if you are attempting to create an e-smith add-on package.
Also, there is a distinction between making use of the services and functions provided and managed by the e-smith system, and making use of the underlying Linux distribution.
The "e-smithed" bits have a finite scope and are more or less well addressed in the manual and by searching the forums or by posting a specific question to the appropriate forum. For example, I am having problems getting PPTP VPN to work -- that is a specific "e-smithed" feature and later today I'll be posing my question in the Experienced forum, but only if I can't find the answer by searching first.
The fact that a Linux distribution, basically a bare bones Red Hat distro, underlies the e-smith layer, means that if you can do it with Linux there is probably a way to do it on e-smith. The limitations are how much time you have to invest and how much knowledge you have of Linux in general, the effects of e-smith-ification on the Red Hat distro, and how to integrate ??? into that framework.
Naturally, the good folks at e-smith and those who monitor and contribute freely to these forums are all happy to help in these types of endeavors if the end result will be something of interest to other e-smithers; however, answers to questions such as "How do I write a CGI script?" or "How do I use qmail?" are likely to go unanswered as they don't convey an e-smith-specific purpose. There are other forums and sites that provide such general information and will answer questions of that ilk, and those are your better bet for such queries. You may find, however, that help is available here if there is a stated e-smith reason, such as "I'm writing a contrib for managing the qmail queue -- how do I create a CGI interface to my queue management program?" That question would surely get a response (well, in devinfo, where it should be posed.)
Cheers
Scott