After restarting the computer, the emails are received by AXIGEN, but they are not delivered, neither locally nor remotely, being kept in the queue.
Issue cause
Some filters were enabled in AXIGEN configuration, but they weren't set to start automatically at system boot.
Solution
In order for the messages delivery to be successfully completed, all the filters enabled in AXIGEN's configuration must be started. Make sure you set these filters to be started each time the system starts, before the AXIGEN is started, so that the delivery to be made successfully.