I have an Exchange 2003 Server on which MOM reported a high Send Queue size. Launched perfmon and monitored the respective counters (MSExchangeIS Mailbox \ Send Queue Size) and noticed that a specific instance is constantly high, increasing slowly by time. All required services running. Checked C:\Program Files\Exchsrv\Mailroot\vsi
1\Queue for pending messages but was empty. Mail flow is still occuring successfuly.
Any ideas on what that queue size is refering to?