Mac/iPhone/iPad imap mail not saving sent message

Sometime after an upgrade, the Mail settings get reset to save Sent messages on the iPhone/iPad.

Here is what to do in order to get your sent messages on the server.
For each email account:

On iPad

Settings>Mail, Contacts, Calendars>Accounts>Choose your IMAP account>Advanced>Mailbox Behaviors>On the Server>Sent Messages.

On iPhone

Settings>Mail, Contacts, Calendars>Accounts>Choose your IMAP account>Advanced>Mailbox Behaviors>On the Server>Sent Messages. (Basically the same thing)