1 - If you have wifi turned on, and are out of wifi range, try turning wifi off. This phone will hunt for a wifi connection forever before it connects via cell tower. If it detects any wifi connection, even if you don't have access it will never connect to email.
2. If you are not using Gmail, there was an update to the preloaded mail app in May.
There is also an update to Gmail that allows you to import mail from other accounts to Gmail. Update it and follow the instructions when it opens. It will prompt you to add other accounts.
These are issues I have seen.
Hope it helps.