How can an applet send email?
The simplest way to answer this question is to tell you to write a CGI program which sends email, and then refer you to the previous question to learn how to communicate with the CGI program. There really isn’t any other reliable, cross-platform way to send email. The problem is that email programs are platform dependent. The Simple Mail Transport Protocol is an Internet standard that you may be able to use some of the time. The basic idea is to open a socket to the SMTP port, 25, on the web server, and send your email through the server. However not all web servers, especially those based on Macs or Windows NT, run SMTP servers, and an applet can’t open sockets to other hosts. Even if you do have SMTP software running on your web server, the applet may be behind a firewall that disallows outgoing connections to port 25 on hosts outside the firewall.