Postfix redirects the emails to my main account and sieve orders them into folders depending on the alias username. I only use one alias for one account. So wh

Postfix redirects the emails to my main account and sieve orders them into folders depending on the alias username. I only use one alias for one account. So when a thirdparty gets that alias i change the alias in database and the account and it gets mapped to my spamfilter.