It seems like a simple task and for the most part it is, but what happens if you set up your IMAP email account and then you get an error message stating this when trying to delete messages:

Unable to Move Message

Well first, let me send you over to an awesome guide for setting up IMAP email on iPhone alongside the Mac app, Mail. The link for this guide can be found here and it contains a very detailed look at the configuration from beginning to end. I only have one piece to add to it.

If you’re getting the message above, it’s simply because by default, iPhone wants to use the Trash, Sent and Draft folders on the phone rather than the same folders on your mail server. What this means is when you try to delete a message, you get an error saying it can’t be moved. For whatever reason, iPhone does not allow you to throw email away in your phone’s trash. My best guess on this would be that it defeats the purpose of IMAP, which is to completely map ALL folders on the server to each of your email devices.

At any rate, the fix is very simple. Follow these steps:

1. Go to the iPhone Settings
2. Tap on Mail, Contacts, Calendars
3. Tap on the email account you wish to edit
4. Scroll down to Advanced
5. Under the header ‘Mailbox Behaviors’, tap on each of the three mailbox folders and check off the identical box under the ‘On the Server’ header.

You’ll see that you’ve changed the folder from being ‘On My iPhone’ to ‘On the Server’. Once the changes have been made, you’ll be in business!