Receiving duplicates

I am receiving copies of my sent emails in both: the sent folder and inbox.

I only want them in my sent folder. I’m using the version: 9.2.1222 (ca10485)

How can I resolve this issue?

What you may be seeing is the Conversation feature. The sent message is not actually in the Inbox, but the conversation which is displayed there includes related messages from all folders. You can disable Conversations by selecting Menu > View > Conversations > Disable Conversations, if that is easier for you.

But if there are actual copies of the sent message in your Inbox, check that you don’t have a Rule you created to move them there, or that you don’t have copies of all sent messages forwarded back to your address.