Message suspense:
Messages can be suspensed in several way: Email
allows delivery receipt and read receipt options to be set at send
(see message receipts). The simplest suspense process is
to set an interval (15 minutes for example) to review priority
messages (sent). Since email date time stamps all messages,
look in the "sent mail" folder and compare sent priority
messages in the last 15 minutes with read receipts ( inbox).