KB01121001 Why are there mail messages stuck in my Outbox?
Mailtraq stores messages that are awaiting delivery in the outbox. When Mailtraq is unable to deliver a message due to some temporary error (such as being unable to resolve the delivery route) it will put a hold on the message and attempt delivery again later.
The small clock symbol that appears on the message icon indicates that the message has been suspended. By default, mail is suspended for 60 minutes before retrying, and after 96 hours it will be returned to the sender. You can configure this by adding an advanced route (Options | Outgoing Mail | Delivery Options tab | Advanced Routing Tables).
You can force Mailtraq to attempt delivery as soon as possible by right-clicking on the Outbox and clicking on Clear Host Assignments. This results in Mailtraq beginning the resolution procedure from scratch (i.e. clearing the host to which the message has been assigned).
See also: Sending Mail without using a SmartHost