Hello,
Sounds like you have big plans for your HDA. It helps to have some linux experience for what you want to do. Unfortunately things such as email is not so easy, especially in the linux world.
1) Use the server as a way to backup 2 Windows machines (xp, vista) and a Mac. How do I get this started?
Recommend you take some time to explore the wiki guidance. There are different third party Windows apps you can install do allow backing up of files to the HDA. I personally use one called Create Synchronicity and works well for me.
2) I want an internal mail server so my family can email each other. I haven't decided if I want this to be accessible from the public Internet, but I assume that I do want that.
This is a bit complicated and not easily done. There may be some guidance on the internet, but your desire requires some technical experience with mail servers and setting them up in Linux. There is no magic app or button to push. Exposing outside your network is even more complicated. It also involves security precautions which would help protect from SPAM and potential viral infections.
3) I would like a network IM server as well.
Others have expressed an interest in this as well. Currently nothing exists in Amahi as an app, however there are probably some things out on the internet to meet this need.
I am not trying to discourage you, but you must understand that not all these things are simple tasks. We do our best to try and capture these types of requirements and document in the wiki or build apps. As with anything else, things often are more complicated than they seem.
Others may be able to offer more help. In the mean time, my recommendation would be to search the internet for tutorials or the Amahi wiki. What is often simple in Windows is more complicated in Linux, at least that has been my experience.
