JSpamfilter is software that intercepts connections from remote Internet mail servers before they can connect to your mail server. The originating IP address for the inbound connection is then checked against one of the DNS-based SPAM Blackhole (DNSBL) lists maintained on the Internet by various organizations. If the check passes, the connection is allowed to proceed to your mail server; if it fails, the connection is told that the mail server is unavailable, then dropped.
Charles is a Web debugging tool, HTTP monitor, and reverse HTTP proxy for Web developers that includes plain text debugging of HTTPS/SSL. It is built in Java Swing, and runs on all Java platforms. It is an HTTP proxy server that displays requests and responses, complete with HTTP headers. This enables the developer to examine the exact content of HTTP exchanges, including cookies, caching, and redirects. It can also throttle your connection in order to simulate modem conditions. It is a valuable tool for all Web developers and is especially useful for debugging XML RCP, SOAP, Web services, AJAX/XMLHTTP, and Macromedia Flash client-server traffic including AMF, AMF 3, LoadVars, and XML Sockets.