When moving or deleting an email on your iPhone you get the error:

Unable to Move Message: The message could not be moved to the mailbox.

iPhone error unable to move message
iPhone error unable to move message

How-to fix

  1. Press the Home button and tap Settings.
  2. iPhone Settings Icon
    iPhone Settings Icon
  3. Scroll down and tap Mail, Contacts, Calendars.
  4. Mail, Contacts, Calendars menu
    Mail, Contacts, Calendars menu
  5. Tap your email account.
  6. Scroll to the bottom and tap Advanced.
  7. iPhone Advanced Menu
    iPhone Advanced Menu
  8. Scroll to the bottom and tap the empty IMAP Path Prefix.
  9. iPhone Imap Path Prefix
  10. Enter INBOX in capitals.
  11. Fixed iPhone IMAP prefix
    Fixed iPhone IMAP prefix
  12. Press the Home button and then re-open Mail.
  13. You can now delete / move your emails as normal.