This is the number of SMS status messages queued by Status Manager to be written to the SMS site database since Status Manager ...

This is the number of SMS status messages queued by Status Manager to be written to the SMS site database since Status Manager was last started. This number equals the number of status messages actually written to the database, unless Status Manager cannot write to the database (because it is full, for example), in which case the number of queued messages (shown by this counter) will increase even though no messages are being written to the database. (Queued messages are stored as .SQL files in \SMS\Inboxes\Statmgr.box
etry.) When the database becomes writable again, the queued messages will rapidly be written to it, and this counter will again reflect the actual number of messages written to the database.