Exchange Server 2007 Standard Anti Spam What Is The Exchange 2007 License Required For My Environment?

What is the Exchange 2007 license required for my environment? - exchange server 2007 standard anti spam

I will upgrade to new versions of my surroundings, but I am confused about my license application. My server will be as follows:

1 - Two servers for mailboxes with CSC (Mailbox01, Mailbox02)
2 - Two servers CAS-HUB (HUB-CAS01, CAS02-HUB)
3 - Two Edge servers (EDGE01, EDGE02)

This is for the main branch

For the other branches of the three functions of the single server Exchange (HUB's, CAS, Mailbox)

Now I have to ask to know how and what license is required, I also know Windows Server 2003 editions, it is necessary for each server (Standard, Enterprise)

Sorry for the long question:)

Please, the answer is organized

Thanks