You have setup imap email on your iPhone/iPad and cannot delete emails. You see the error “Unable to move message – The message could not be moved to the mailbox Trash”.
– Go into settings -> Mail, contacts, calendar
– Go into your email account
– Scroll down to the bottom and click advanced
– Tap on IMAP Path Prefix
– Enter INBOX in capitals.
– Click on accounts on the top left and also click done and then done again. (If this step is not done it will not work)
Did this help you? I had a client the other day which this fixed her issue.