Hi PB8,
Can i get you to check the following?
log into webmail, down the lefthand side of the page is the MY EMAIL menu. At the bottom of the list you'll see an option call My Folders. On the left hand side of My Folder there will be an arrow (>) pointing to the words. Click on the arrow to expand and you will see any extra folders.
Usually if you are using an Apple device, like an iPhone or iPad, set up for IMAP the default mail app will automatically create its own folder called Sent Messages(a) and store email sent from the iPhone in that folder rather than using the normal Sent Folder(b).
If you see a folder in there called Sent Messages, click on it to open it and you should see the email sent from Apple devices. This can be changes and the messages moved as explained above.