On Windows Phone, you can link as many of your inboxes as you’d like, so you can see and respond to all of the email from those accounts from the same inbox. But if you’d prefer to keep some inboxes separate, you can do that too.

Link inboxes

1. On Start, tap an email account that you want to link to another account.

2. Tap More   >> Link inboxes.

3. In the Other inboxes list, tap any inboxes you want to link to this one. As you tap them, they’ll move into the This inbox list.
4. Tap Rename linked inbox, delete the existing name, type a new name, then tap Done. The newly linked inbox Tile will appear on Start.

Unlink inboxes

1. On Start, tap a linked email account.

2. Tap More   >> Linked inboxes.

3. In the This inbox list, tap each account you want to unlink, and then tap Unlink. The inbox moves to the Other inboxes list.