Connection to server failed on ipad

Does anyone have a fix for this. I had this problem and I deleted all my email accts and then created them new, and everything seemed to work for a while. I synced my ipad and iphone a few days ago, and now we're back to the same issues again! Please someone tell me how to fix them. I have a realtor and I was out of the office all day, and couldn't get my email until 3:00 this afternoon. HELP!!!