I recently hadf a problem on my iPhone 4s where i was unable to delet mails from one of my mailboxes. Everytime i tried to delete an email from the inbox in question I got an error stating ‘Unable to move message to folder Trash’. Here is the simple fix that solved the issue for me.
- Open Settings
- Select Mail, Contacts, Calanders
- Select the mail box affected
- Select Advanced
- Select Deleted Mailbox
- Click on Trash (even though it may already be checked)
As soon as I did this ti was suddenly able to successfully delete emails form my inbox again. Simples!