Why are emails sent using my iCloud IMAP account from my Blackberry Keyone Android Smartphone putting my sent emails into the Sent Items Folder on the iCloud server, not the Sent Mailbox.

So I have two places where Sent Mail is shown, Mail from iMac, other devices, go into the Sent Mailbox, and the Keyone puts sent emails into the Sent Items folder.

Why do I need iCloud Folders???

I want everything to go into the Sent Mailbox.

Comments?