Spotlight on exchange and Spotlight on Messaging highlights Send Queue in a Red state, a number of messages are queued.
Searching through the Queues on Exchange System Manager does not show any pending messages. Is Spotlight on Messaging reporting inaccurately?
If a relatively small number of messages appear stuck in the outgoing store queue and cannot be accounted for, they could be messages that one or more users have marked for future delivery. A user can do this using the "Do not deliver before" option of the Outlook mail client when composing a new message. The message is composed and stored in the user's "Outbox", and the Exchange store increments its outbound message store count until the message is sent to the recipient at a later date. The below Microsoft Articles may assist in troubleshooting further.
To confirm Spotlight is reading the correct information use the following method:
1. Access Performance Monitor on the Spotlight computer (start / run perfmon), and choose 'Add a counter'. Enter the name of the Exchange Server being monitored. Add the 'MSExchangeIS Mailbox' performance object, and the 'Send Queue Size' counter.
2. Compare the number displayed in the 'Last' Column to the number that Spotlight on Messaging is displaying in the Send Queue size.
If the above research shows the same results you may wish to adjust the metrics for this counter in Spotlight on Messaging (so it will not show red).
Steps to change metrics:
Right-click the Send Queue counter in Spotlight on Messaging- Metrics - Thresholds Tab - Uncheck the box next to "store send queue" to turn off monitoring for that counter.