The primary concerns in existing Email and instant messaging systems are authentication processes, privacy and security issues. These messaging systems transfer the message content through servers using protocols like the Simple Message Transfer Protocol (SMTP), Post Office Protocol (POP), and Internet Message Access Protocol (IMAP) to allow users to communicate. During these processes, messages are being stored on the servers which can be easily accessed by the network administrator. Invasion of privacy, integrity of Email content, lack of authentication, and unprotected back-up of messages stored · on servers could be common underlying problems in the existing architecture. The goal of this paper is to build· an Email messaging system which would offer better privacy and security of Email content to users. The application can be viewed as a source of communication for people in a private club. In this paper we propose three different designs for building an email messaging system using the Java Agent Development Environment (platform to provide communication between agents) framework. Our application mainly uses intelligent software agents. The three Designs primarily implement two kinds of software agents, a Facilitator Agent and P-Mail (PrivateMail) agent. Based on the Design and architecture these agents act accordingly to meet the user requirements and provide better security and privacy. Finally we conclude by evaluating the three designs by assessing their performance.