I have created an email account, firstname.lastname@example.org. I have created an alias for that account, email@example.com. Now, emails to firstname.lastname@example.org are delivered to the INBOX of email@example.com. This is great. Even better would be to deliver emails to firstname.lastname@example.org to the TRASH folder for the email@example.com account. I use several different clients for this account. How do I do this on the server side? Thank you.
Add a sieve rule in SOGo (or via your email client).