Note: If your mail is backing up in the ...\gwia\3rd\send directory or the ...\gwia\receive directory, then you're probably dealing with a GroupWise issue, not GWAVA
Follow these steps to narrow down the problem:
1) Restart GWAVA and check mail flow again in 5 minutes. This resolves the issue more times than not. Keep in mind that GWAVA may take quite a while to catch up if there is a lot of mail queued up. Be patient. As long as the queue directories are depleting, then eventually it will catch up. If you are having to restart GWAVA frequently to resolve mail flow issues, however, then you should call technical support to diagnose the issue
2) If your daily mail flow is high, then you may need to increase your GWAVA threads. See: https://support.microfocus.com/kb/doc.php?id=7020571
3) If steps 2 and 3 were unsuccessful, then you're probably having a problem with a specific GWAVA event. You'll need to call in to support to delve deeper.