Exchange queues not delivering

I have exchange on SBS2011 and mid morning the email stopped receiving mail.  I use Popconn to collect the mail from a pop account and it seems this got stuck in a loop trying to deliver an email larger than the file size setting on exchange.  As a result it seemed to create some 40GB of emails over two days.  Hence the server almost ran out of disk space which I suspect caused the initial problem.

Now exchange is not working correctly.  After a restart it seems to be able to send email and clients and iphone can send, connect and search for emails.  However, it does not seem to deliver the inbound emails that it must have been given by popconn earlier.  Also, there are only 4 queues of which the Poisen queue has 9 emails that I can seem to delete and when I try to view the messages nothing is displayed.

When I run the Queue tool if I send an email from my iphone externally it is not sent.  This seems to produce an Event error:

Watson report about to be sent for process id: 11140, with parameters: E12, c-RTL-AMD64, 14.01.0438.000, edgetransport, M.E.Extensibility.Internal, M.E.D.M.I.MimeCacheMap.Load, M.E.D.Mime.MimeException, 562d, 14.01.0438.000.
ErrorReportingEnabled: False.

Then another error occurs:

The Microsoft Exchange Mail Submission service is currently unable to contact any Hub Transport servers in the local Active Directory site. The servers may be too busy to accept new connections at this time.

In the Queue in the bottom left of the window it shows over 100 processes and rising.

I suspended on of the queues as it has an error next to it 421 Refused.

If I try to restart the transport service if hangs but I can start all of the services from the Topology service.

I am considering deleting the mail.que file as I need to get thnis working by the morning but I'd rather not take this approach unless necessary.

thanks in advance.