Mail.box Database Hook using C API Toolkit

Hello.I already searched the internet and the Domino 4/5 and 6 Forum.

I want to write a C (C++) DLL to make changes to documents in the mail.box before the router delivers the mail to the recipients.

I only found parts of sourcecode and no detailed description about how the api works.

I know, I have to set a Notes.ini variable and to use the C API Toolkit to write the DLL.

Do you have a small sample sourcecode with short description about mail.box hooking?

Thank you

Martin