Different Sent Mail Folders for Phone and Computer

I am using my cox email account on my computer (Outlook with IMAP) and my Phone (iOS mail).

The inbox is common on the devices and Webmail but when I send an email from my computer - it ends up in the Sent Objects folder in Webmail, and email sent from my iPhone ends up in a folder called Sent Messages under My Folders in Webmail.

Both devices show all of the folders reflected in WebMail

How do I make both devices send to the common Sent Objects folder?