If your iPhone / iPad has been working but all of a sudden is unable to connect to our server, make sure you have a good wifi connection. You can check if your internet is active and is not "down" by trying to go online with another device or computer nearby, or you can open up Safari on your device and try going to http://webmail.emailpros.com to see if it loads.
If you are on 3G/4G, sometimes when you are moving around and changing cell towers, you may lose connection to our servers. Just move to a better spot and it should re-establish a new connection to our server.
If all else fails:
Your device is a mini computer, sometimes it needs to be rebooted. Tap the home button twice to bring up all active apps, hold down an app until they all wiggle, you should see a red "-" icon appear, tap that red "-" left corner to close down all your active apps. Once you are done closing all your apps, tap the home button again to return to the home screen. Power down your device, wait for it to turn off completely, then power it back up. 99% of the time this fixes connection issues.