Try going to Settings -> Applications -> Manage Applications, finding Gmail (in the All tab), and clearing cache and data (don't worry about losing data, it's only temp/cache data you're deleting). When you open GMail again, it should say "Your email will appear shortly," and if everything goes well, connectivity should return.
Alright I tried the clearing data step sand that did not work for me. So I just tried a simple reboot of the phone and it worked. Ty for your help brother!