If you setup your email account with an IMAP connection across multiple iOS devices, you may experience an issue on your iPhone or iPad where can see your Inbox but you do not see folders other than Inbox. Fortunately, if you do experience this issue, there is an easy fix.
If the IMAP Path Prefix is not set, then you may see the following error message:
Specify the IMAP Prefix
- Select "Settings" on your iOS device
- Scroll down the menu and choose "Mail, Contacts, Calendars"
- Select the account you wish to modify
- In the next screen, select your account again
- Choose Advanced at the bottom of the next screen
- Enter "INBOX" (all caps, without the quotes) in "IMAP Path Prefix"
- Tap the "Account" button in the upper left of the screen
- Tap "Done" back in the upper right of the Account screen to save your changes
You should now be able to view your other folders on your iOS device.