Hi, I have a T-Mobile Sidekick II.  I am looking for a link or so that
can give me a solution that I can use to check corporate email from my
device.

I already know about paying $100 for the intellisync service, but I
was thinking that it could be possible to view my email through
thunderbird or microsoft outlook as follows:

-Have my corporate email downloaded onto my own computer
-Have the emails go into my computer and be forwarded to another email account
(can email checking programs do this automatically?)
-My sidekick II already has access to Gmail, so I can just read the
corporate emails from my phone.

If you have a way to forward the corporate emails to a gmail account
(or any regular web-based acct, really), please tell me.

Even better, if there is a way that I can access my company's
corporate webmail, please let me know about that!

Does your company allow you to connect via POP3?  If they do then just
add a new email acct on you sidekick with the propper settings for
your server.  if you dont know the answer to this then call your IT
dept and ask them.