Using MMPs and MEMs

The MMP enables you to mask the layout of your Messaging Server hosts from your end users. Consequently, you assign users to a generic MMP or a load balancer without having them point to the specific server where their mail boxes reside. Message access clients point to the MMP for retrieving incoming messages.

When such a client connects and authenticates, the MMP looks up the user information in the directory to determine where the user’s messages are held. The MMP then connects the client to that specific server. The following figure shows how the MMP acts as a proxy for IMAP4 and POP3 connections to Messaging servers. You can multiplex HTTP services (like Messenger Express) by enabling the MEM feature. Figure 12–6 shows how multiplexors function in a Messaging Server environment.

Figure 12–6 MMP Overview

Use a load balancer in front of the multiple MMPs. It is unlikely that you would have a single MMP.