Only authorized users (with Administrator Privileges) will have permission to edit the status values of messages. You can change user permissions in the Advanced tab.
You can easily change the status of each message to either "W" (re-queues the message), or "Hold" (message with status changed to prevent it from being sent).
To change the status of a message:
Click the Routing tab. The Routing page appears.
Under Number of Sub-Channels, click the inbound channel containing the message you want to change the status for. The Inbound Channel Status page appears.
Scroll down to the Status Table, and navigate to the message you want to edit using the controls at the top (First Page/Prev Page/Next Page/Last Page).
Click the Key column of that message. The Message Status screen is displayed. The top of the page shows the entire message (read-only) and the message's current status for each sub-channel.
Message Status Screen
Change the status value of the message to either "W" - Waiting/Queued or "Hold".
Click Apply to confirm your changes. The message's status value is immediately updated in the status window.