The Quarantine Plus feature enables you to view messages that have not been delivered to your mail server yet. This can be helpful if your mail server is offline and you want to see who has tried to email you.
Here's how to view messages queued for delivery:
1) Go to the Quarantine+ tab in the SpamHero control panel and select Queued for delivery from the drop-down list (on the upper right side of page).
2) Use the logs option to view the logs for individual messages and determine why the delivery is being held up:
3) After resolving the issue that is not allowing the emails through, our mail server will eventually deliver all messages queued for delivery. Or, you can re-attempt delivery of all messages queued for delivery within 15 minutes by going to the Tools > flush mail queue option: