How to sync your Sent Items, Drafts and Trash with IMAP on iPhone.

Once you are on your iPhone home screen do the following:

1. Go to Settings and select “Mail, Contacts, Calendar” option.
2. Select your IMAP account and choose the account (user@example.com)
3. Scroll down and select “Advanced”.
4. Change “Mailbox Behaviors” for Sent items (Choose Sent Mailbox)  
   Then you want to select from Below on what folder you want to save it to on the Server
   Repete Seps for Drafts, and Trash if you want to save them on server as well.
5. Go back to Advanced (top left) then back to Account (top left)
6. Choose Done to save.