www4mail is designed to replicate, as closely as possible, the experience of browsing the Web via a full Internet connectionincluding the search of online databases by optimizing the resources. www4mail has also broken new ground in flexibility for the Web-to-email service provider, offering comprehensive management facilities such as:
Web server style logging of access: allows the usage of www4mail to be monitored and graphed by standard Web statistics programs.
Access control: can be used to restrict access to particular user groups like non-profits or particular regions in developing countries.
Content filters: can be used to prevent abuse of the www4mail program by users attempting to use www4mail to access inappropriate material.
Dynamic Page Contents
Documents in Frames
When www4mail encounters an HTML page with frames, it dynamically kicks in a set of modules for each frameset and frame tag encountered. The modules essentially perform a HTML frame to HTML table conversion process. The end result resembles the equivalent framed page quite closely, but lacks the ability to scroll within frames.
To retrieve binary files, www4mail sends them as MIME base 64 encoded attachments, except when the user has requested uuencoding.
In order to connect with secure Web sites using "https://", www4mail depends on either the "stunnel" or "curl" program. Stunnel is a program that allows encryption of arbitrary TCP connections inside SSL (Secure Sockets Layer), while curl is a general-purpose download utility/browser similar to the Lynx browser. When using stunnel, www4mail treats https as a normal http connection (using it's internal browser) except that the TCP connection is made via stunnel. However, when working via curl, curl is handed the URL and expected to provide the final HTML document. In the www4mail sense, stunnel is a "helper" application for the https protocol while curl is called a "handler" for the https protocol. A handler replaces the internal browser while a helper augments its functionality. Other protocols such as "news://", "ftp://", and "gopher://" are supported via Lynx working in the handler mode.