Email is classified as "Sent" or as "Received" depending on the "From" and "To" fields of the email. If the email's "From" is the account's email address then the email is shown on the "Sent" folder. If the email's "To" contains your email address then the email is shown on the "Inbox". If your email is in "From" and "To" it should be shown in both folders.
Does this explain your case or are you seeing all email "From" your email address in the "Inbox"?
