Sorry, but I'm confused by your question. Your entries on the Identities page only changes the choices you have to change your From address when sending. They do not affect receiving email.
- If you go to the Settings>Identities & Fetch page, you will see one or more Send Mail As identities at the top. You can edit each of these, and while editing you can click Show advanced preferences to change more features (such as creating a Nickname only visible to you). You can remove that sending identity using the Remove Account button while editing an identity.
- Below this is a tool which lets you select your default identity.
- What are you calling your "main entries"?
- Why did you place two identical email addresses on your question?
Bill