The following schematic outlines the process with which eNewsletter Pro manages and delivers newsletters.  The basic process is as follows:  The administrator creates one or more user accounts.  These users then manage their newsletter lists, newsletters, subscribers, reporting, opt-outs, bounces, etc.  Users then submit the newsletter to the queue for delivery.  If the administrator requires approval of each newsletter, the administrator must approve the newsletter before it is delivered.  

Newsletters in the Queue are then picked up by the eNewsletter Pro Mail Engine.  By default this engine checks for pending newsletters every 2 minutes.  If a pending newsletter is found the individual email messages are created and submitted to the mail server for delivery.  The mail server can maintain up to 64 simultaneous connections for fast email delivery.  Every 8 minutes the eNewsletter Pro bounce engine scans for bounced email messages and records all email address that have bounced.