I have Zimbra up and working on a test server. Looks very nice and my company is considering a migration from our current system (qmail, courier Imap). Now I am wondering about the limits on the incoming and active queues. The admin document says there is a limit on the number of messages in the active queue. What about incoming?

I am particularly curious about how Zimbra will handle local clients. Our current system has trouble because the mail scanner will not accept incoming smtp messages until there is a process available. this causes long waits for mail to be accepted (on the client side) or sometimes even dropped smtp connections. How does Zimbra handle local smtp connections in this regard?