Here is advice on why your email is sending multiple copies:

1. Check if you have configured multiple email accounts in the program.
2. Check if you have a rule configured to sync emails from multiple folders to one mailbox or between accounts.
3. Check if you have an auto-forwarding rule set for the mailbox.
4. Check if you are subscribed to newsletters that are being forwarded to the account.
5. Check if you have set up an account to forward mail to another mailbox.