Need StealthMTA expert

I have StealthMTA setup with 1 main server and 1 cluster with 4 IPs.

When I send emails the queue is always growing and never decrease.
Even if I stop sending in Interspire the queue stays there for 3-4 days.

The only solution I have is to clear the queue before it reaches 10,000 and resume sending.

But this way I can't leave the sending on its own and have to always interfere.

I suppose those messages in the queue get never sent.

If you know how to fix this bug in StealthMTA please contact me through PM or post here.

Have you found the solution for this issue?

I've given up on StealthMTA and got onto Sendy.