Some customers have reported that Microsoft Vista does not work like Windows XP, 2000 and 95 have with e-mail and the web. We picked up this solution from the web to turn off a networking feature of Vista which seems to cause some of these problems.
Go to Programs>Accessories, right-click on Command line (cmd) and run as administrator.
At the prompt type:
netsh interface tcp set global autotuninglevel=disable