Complete Messaging center for auction site jsp / j2ee

We need a complete messaging center for our auction site project. The message center should have the same functions like the ebay messaging center or e.g. hotmail / yahoo mail / gmail and so on. > if customers are communicating together all should work completely through our message center - just on our site. Customers should only receive an infomail that they have a new e-mail - able to recheck in our messaging center. For further information please send me a private message. Our existing site the message center needs to be implemented into - is in j2ee / JSP. You can use an open source center or develope it from the beginning. The message center is very important for us - but we have no time programing it ourselves. Quality is most important to us. We will need to recheck a sample code of you to see if your experience is reaching our expectations. We will do the implementation into our source code. If the center is working as imagined and spoken before the development - we will pay you immediately out! We won´t escrow money again. We did it in the past and had to pay for a work quality we wouldn´t generally pay for. If you do a good job - you get a good price! Fairplay on both sites.