Someone PM and asked me what this plug-in is. I will reply here as well with the answer.
DNP is a Provider based interface, you can write your own interfaces to different applications, like IIS, exchange, hMail, etc...Once you write the interface you just register it within DNP, and it shows up as a available provider when you add a mail/web/dns/etc server.
All the interfaces today are written solely by DNP, and since I moved to hMail 5 and DNP hasn't written the provider yet, I wrote one myself.
I am currently writing another for MsFTP 7, to use the isolated user mode.