Where is the queue stored?

I have been using phplist for a while now and I am comfortable using it, but I believe I may have accidentally made a mistake where I deleted a message in the queue.
Some mails have been sent, but most haven’t.
I am trying to figure out where I can find the queue to see if there are mails left there.
Where does phplist store the queue? How does this work exactly?
I cannot seem to find a queue in the database so how does it keep track of it?

@vampster there isn’t a queue as such. The “queue” is those campaigns that have a the “submitted” status.
It is actually quite difficult to delete a campaign once it has been submitted. Possibly you have only changed the status. In which case it may be on the Draft or Sent tabs.

Thanks for your reply. The campaign has litterally disappeared, I can not find it anywhere, not even in the database. Not sure what happened there…
There must be a queue somewhere? How does the software tracks the mails it must send?

@vampster once the campaign has started sending you can only stop it and find it in the “Active” tab so you can resume it later or you can mark it as sent and find it listed in the “Sent tab” as Duncan mentioned.