replacing tcpserver

Hi,
I would like to migrate from tcpserver to tcpsvd (the per host 
concurrency feature is great!) but after going through Gerrit's page and 
  the list I still don't understand if I can accomplish pop-before-smtp 
functionality in the same way as I do today.

In my working setup with qmail+vpopmail+ucspci, vpopmail rebuilds the 
tcp.smtp.cdb file every time a client authenticate via pop. Vpopmail 
uses tcprules to do this. Can I tell vpopmail to use ipsvd-cdb instead 
to rebuild tcp.smtp.cdb or is there another way of accomplish 
pop-before-smtp with my current setup?

regards, Karim