If you’re receiving duplicate emails even though you only have one account set up, here are some common causes and remedies:

1. Check your filters and make sure that emails aren’t being accidentally forwarded or duplicated.
2. Check your Rules and make sure that emails aren’t being accidentally filtered into a folder.
3. Check your synchronization settings and make sure that emails are not being copied from one client to another.
4. Clear your mailbox cache and remove any duplicate emails that may already be in your inbox.
5. Check for spam messages that may be targeting your mailbox.