A4Proxy doesn’t work with ordinary e-mail software clients like Outlook and Eudora. You can use it only with your web browser or download manager like GetRight. However, you can still send e-mail anonymously using web-based e-mail services like HotMail.com. When you connect to their web interface through A4Proxy and send e-mail using their web-forms, your IP address is hidden from them and it is not present in the e-mails you send. You can easily test it by sending an email to yourself and looking at the headers of the message when it arrives.
The situation is the same with newsgroups. You can’t use A4Proxy with an ordinary newsreader, but you can read and post messages anonymously with a web-based news service, like Google Groups. As long as you use A4Proxy and the web interface of the Google service, you are anonymous.
A4Proxy doesn’t work with IRC or ICQ.