Code whatever hits your mind - the more you program in the Python the easier it becomes to "think in Python", meaning you code faster and write higher quality code.
libgmail is pretty nice to fool around with - a little buggy at times, yet useable.
I had issues with msnp as the version I used wouldn't respond to a forwarding for authentication sent by the MSN server, but that may be fixed now. I ended up writing a wrapper around msnlib which, although lacking in docs too, worked for me.
Have fun whatever you do
