Email client requests message to read from Messaging Server Multiplexor (MMP).
MMP requests message from Messaging Server Message Store (STR).
STR returns message to MMP.
MMP forward message to email client.
Email client sends deletes message action to MMP.
MMP forwards delete message action to STR.
STR deletes message from database and sends confirmation to MMP.
MMP forwards delete confirmation to email client.