You will get an error like "Your IMAP server has closed the connection. This may occur if you have left the connection idle for too long" by changing this setting.
To Resolve: Edit
1. Go to File - Tools - select E-mail Accounts.
2. Select View or change existing e-mail accounts and click Next.
3. Select the e-mail you want to modify and click Change.
4. To bring up the Internet E-Mail Settings window, click More Settings.
5. Select the Advanced tab.
6. Left click on the slide-point and drag to the far right side (10 minutes).
8. Click Apply and then OK.